mdev: do not exit if user:group parse failed. closes bug 309.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index e23828e..99e4875 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -241,7 +241,8 @@
 			 * the rest the line unless keep_matching == 1 */
 
 			/* 2nd field: uid:gid - device ownership */
-			parse_chown_usergroup_or_die(&ugid, tokens[1]);
+			if (get_uidgid(&ugid, tokens[1], 1) == 0)
+				bb_error_msg("unknown user/group %s", tokens[1]);
 
 			/* 3rd field: mode - device permissions */
 			mode = strtoul(tokens[2], NULL, 8);