cherry-pick/revert: more compact user direction message

A failed cherry-pick (and friend) currently says:

|Automatic cherry-pick failed.  After resolving the conflicts,
|mark the corrected paths with 'git-add <paths>'
|and commit the result.

This can obviously be displayed on two lines only.
While at it, change "git-add" to "git add".

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin-revert.c

@@ -351,7 +351,7 @@ static int revert_or_cherry_pick(int argc, const char **argv)
 			die ("Error wrapping up %s", defmsg);
 		fprintf(stderr, "Automatic %s failed.  "
 			"After resolving the conflicts,\n"
-			"mark the corrected paths with 'git-add <paths>'\n"
+			"mark the corrected paths with 'git add <paths>' "
 			"and commit the result.\n", me);
 		if (action == CHERRY_PICK) {
 			fprintf(stderr, "When commiting, use the option "