lualoader: Use global printc instead of loader.printc

r330282 registered loader.printc as printc, so use it instead. This makes
sense for a couple reasons, the major point being that it reads a little bit
easier and pairs nicely with the global 'print'.

Similar cases can not really be made for other loader.* functions as most of
them are either highly specific to our use-case or usually available in
other modules, such as `os`. printc does not have a standard implementation
in the Lua world(*), so we have a little more leeway with it, and it's kind
of a special case of the globally available 'print'.

(*) I've been in the Lua world for all of two weeks, so this could be wrong.

stand/lua/drawer.lua

@@ -358,30 +358,30 @@ function drawer.drawbox()
 	local tr = framespec.top_right
 	local br = framespec.bottom_right
 
-	screen.setcursor(x, y); loader.printc(tl)
-	screen.setcursor(x, y + h); loader.printc(bl)
-	screen.setcursor(x + w, y); loader.printc(tr)
-	screen.setcursor(x + w, y + h); loader.printc(br)
+	screen.setcursor(x, y); printc(tl)
+	screen.setcursor(x, y + h); printc(bl)
+	screen.setcursor(x + w, y); printc(tr)
+	screen.setcursor(x + w, y + h); printc(br)
 
 	screen.setcursor(x + 1, y)
 	for _ = 1, w - 1 do
-		loader.printc(hl)
+		printc(hl)
 	end
 
 	screen.setcursor(x + 1, y + h)
 	for _ = 1, w - 1 do
-		loader.printc(hl)
+		printc(hl)
 	end
 
 	for i = 1, h - 1 do
 		screen.setcursor(x, y + i)
-		loader.printc(vl)
+		printc(vl)
 		screen.setcursor(x + w, y + i)
-		loader.printc(vl)
+		printc(vl)
 	end
 
 	screen.setcursor(x + (w / 2) - 9, y)
-	loader.printc("Welcome to FreeBSD")
+	printc("Welcome to FreeBSD")
 end
 
 function drawer.draw(x, y, logo)

stand/lua/password.lua

@@ -45,14 +45,14 @@ function password.read(prompt_length)
 	local twiddle_pos = 1
 
 	local function draw_twiddle()
-		loader.printc("  " .. twiddle_chars[twiddle_pos])
+		printc("  " .. twiddle_chars[twiddle_pos])
 		-- Reset cursor to just after the password prompt
 		screen.setcursor(prompt_length + 2, screen.default_y)
 		twiddle_pos = (twiddle_pos % #twiddle_chars) + 1
 	end
 
 	-- Space between the prompt and any on-screen feedback
-	loader.printc(" ")
+	printc(" ")
 	while true do
 		local ch = io.getchar()
 		if ch == core.KEY_ENTER then
@@ -61,7 +61,7 @@ function password.read(prompt_length)
 		if ch == core.KEY_BACKSPACE or ch == core.KEY_DELETE then
 			if #str > 0 then
 				if show_password_mask then
-					loader.printc("\008 \008")
+					printc("\008 \008")
 				else
 					draw_twiddle()
 				end
@@ -69,7 +69,7 @@ function password.read(prompt_length)
 			end
 		else
 			if show_password_mask then
-				loader.printc("*")
+				printc("*")
 			else
 				draw_twiddle()
 			end
@@ -87,23 +87,23 @@ function password.check()
 		local attempts = 1
 
 		local function clear_incorrect_text_prompt()
-			loader.printc("\n")
-			loader.printc(string.rep(" ", #INCORRECT_PASSWORD))
+			printc("\n")
+			printc(string.rep(" ", #INCORRECT_PASSWORD))
 		end
 
 		while true do
 			screen.defcursor()
-			loader.printc(prompt)
+			printc(prompt)
 			local read_pwd = password.read(#prompt)
 			if pwd == nil or pwd == read_pwd then
 				-- Clear the prompt + twiddle
-				loader.printc(string.rep(" ", #prompt + 5))
+				printc(string.rep(" ", #prompt + 5))
 				if attempts > 1 then
 					clear_incorrect_text_prompt()
 				end
 				return read_pwd
 			end
-			loader.printc("\n" .. INCORRECT_PASSWORD)
+			printc("\n" .. INCORRECT_PASSWORD)
 			attempts = attempts + 1
 			loader.delay(3*1000*1000)
 		end

stand/lua/screen.lua

@@ -41,7 +41,7 @@ function screen.clear()
 	if core.isSerialBoot() then
 		return
 	end
-	loader.printc(core.KEYSTR_CSI .. "H" .. core.KEYSTR_CSI .. "J")
+	printc(core.KEYSTR_CSI .. "H" .. core.KEYSTR_CSI .. "J")
 end
 
 function screen.setcursor(x, y)
@@ -49,25 +49,25 @@ function screen.setcursor(x, y)
 		return
 	end
 
-	loader.printc(core.KEYSTR_CSI .. y .. ";" .. x .. "H")
+	printc(core.KEYSTR_CSI .. y .. ";" .. x .. "H")
 end
 
 function screen.setforeground(color_value)
 	if color.disabled then
 		return color_value
 	end
-	loader.printc(color.escapef(color_value))
+	printc(color.escapef(color_value))
 end
 
 function screen.setbackground(color_value)
 	if color.disabled then
 		return color_value
 	end
-	loader.printc(color.escapeb(color_value))
+	printc(color.escapeb(color_value))
 end
 
 function screen.defcolor()
-	loader.printc(color.default())
+	printc(color.default())
 end
 
 function screen.defcursor()