mfc-candidates: move pretty printing into lua

d51c590023 moved the MFC hash matching logic into a lua utility
script but left the output formatting in the shell script. Simplify this
slightly by just printing the formatted output from lua.

Sponsored by:	The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D44836

tools/tools/git/candidatematch.lua

@@ -36,6 +36,14 @@ local function set_difference(set1, set2)
 	return result
 end
 
+-- Execute a command and print to stdout
+local function exec_command(command)
+	local handle = io.popen(command)
+	local output = handle:read("a")
+	handle:close()
+	io.write(output)
+end
+
 -- Main function
 local function main()
 	local from_file = arg[1]
@@ -59,7 +67,7 @@ local function main()
 
 	-- Print the result
 	for _, hash in ipairs(result_hashes) do
-		print(hash)
+		exec_command("git show --pretty='%h %s' --no-patch " .. hash)
 	end
 end
 

tools/tools/git/mfc-candidates.sh

@@ -152,7 +152,6 @@ canonicalize_hashes()
 workdir=$(mktemp -d /tmp/find-mfc.XXXXXXXXXX)
 from_list=$workdir/commits-from
 to_list=$workdir/commits-to
-candidate_list=$workdir/candidates
 
 if [ -n "$exclude_file" ]; then
 	exclude_list=$workdir/commits-exclude
@@ -163,10 +162,6 @@ commits_from "$@" > $from_list
 commits_to "$@" > $to_list
 
 /usr/libexec/flua $(dirname $0)/candidatematch.lua \
-    $from_list $to_list $exclude_list > $candidate_list
-
-while read hash; do
-	git show --pretty='%h %s' --no-patch $hash
-done < $candidate_list
+    $from_list $to_list $exclude_list
 
 rm -rf "$workdir"