rebase -m: don't print exit code 2 when merge fails

When the merge strategy fails, a message suggesting the user to try
another strategy is displayed. Remove the "$rv" (which is always equal
to "2" in this case) from that message.

Signed-off-by: Martin von Zweigbergk <martin.von.zweigbergk@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-rebase--merge.sh

@@ -78,7 +78,7 @@ call_merge () {
 		die "$resolvemsg"
 		;;
 	2)
-		echo "Strategy: $rv $strategy failed, try another" 1>&2
+		echo "Strategy: $strategy failed, try another" 1>&2
 		die "$resolvemsg"
 		;;
 	*)