msgfmt: remove unused error() function

fixes a warning:
msgfmt.c:202:2: warning: format not a string literal and no format arguments [-Wformat-security]

Author: midipix

src/msgfmt.c

@@ -198,11 +198,6 @@ static char** sysdep_transform(const char* text, unsigned textlen, unsigned *len
 	return out;
 }
 
-static void error(const char* msg) {
-	fprintf(stderr, msg);
-	exit(1);
-}
-
 static inline void writemsg(struct callbackdata *d) {
 	if(d->msgidbuf1_len != 0) {
 		if(!d->strlist[d->curr[pe_msgid]].str.off)