mergetool: don't suggest to continue after last file

Eliminate an unnecessary prompt to continue after failed merger, by
not calling the prompt_after_failed_merge function when only one
iteration remains.

Uses positional parameters to count files in the list to make it
easier to see if we have any more paths to process from within the
loop.

Signed-off-by: Nicholas Guriev <guriev-ns@ya.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-mergetool.sh

@@ -491,14 +491,16 @@ main () {
 	printf "%s\n" "$files"
 
 	rc=0
-	for i in $files
+	set -- $files
+	while test $# -ne 0
 	do
 		printf "\n"
-		if ! merge_file "$i"
+		if ! merge_file "$1"
 		then
 			rc=1
-			prompt_after_failed_merge || exit 1
+			test $# -ne 1 && prompt_after_failed_merge || exit 1
 		fi
+		shift
 	done
 
 	exit $rc