fix handling of multiple untracked files for git mv -k

The "-k" option to "git mv" should allow specifying multiple untracked
files. Currently, multiple untracked files raise an assertion if they
appear consecutively as arguments. Fix this by decrementing the loop
index after removing one entry from the array of arguments.

Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin-mv.c

@@ -192,6 +192,7 @@ int cmd_mv(int argc, const char **argv, const char *prefix)
 					memmove(destination + i,
 						destination + i + 1,
 						(argc - i) * sizeof(char *));
+					i--;
 				}
 			} else
 				die ("%s, source=%s, destination=%s",