net/echoping: fix the segmentation fault at dns.c:111

Add missing prototype for to_upper() which returns char *.  Without it,
compiler assumed that it returns an int, which results in segmentation
fault in init() at dns.c when trying process its result which had been
cast to char *, albeit needlessly (this code does lots of bogus casts).

PR:	220294

net/echoping/Makefile

@@ -2,7 +2,7 @@
 
 PORTNAME=	echoping
 PORTVERSION=	6.0.2
-PORTREVISION=	7
+PORTREVISION=	8
 CATEGORIES=	net
 
 MAINTAINER=	ports@FreeBSD.org

net/echoping/files/patch-echoping.h

@@ -43,3 +43,11 @@
  
  /* My functions */
  
+@@ -198,6 +186,7 @@ int TLS_readline ();
+ #endif
+ /* util.c */
+ char *random_string ();
++char *to_upper(char *);
+ void tvsub ();
+ void tvadd ();
+ void tvavg ();