query_fileowner: avoid buffer overflow

Copying a string into a buffer that  has just been determined to not be
able to hold it is obviously incorrect.  The actual error handling
appears to have been unintentionally removed in
47762ab687.

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>
Signed-off-by: Allan McRae <allan@archlinux.org>

src/pacman/query.c

@@ -204,6 +204,7 @@ static int query_fileowner(alpm_list_t *targets)
 			size_t rlen = strlen(rpath);
 			if(rlen + 2 >= PATH_MAX) {
 					pm_printf(ALPM_LOG_ERROR, _("path too long: %s/\n"), rpath);
+					goto targcleanup;
 			}
 			strcat(rpath + rlen, "/");
 		}