kobj_uevent: Ignore if some listeners cannot handle message

kobject_uevent() uses a multicast socket and should ignore
if one of listeners cannot handle messages or nobody is
listening at all.

Easily reproducible when a process in system is cloned
with CLONE_NEWNET flag.

(See also http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/5256)

Signed-off-by: Milan Broz <mbroz@redhat.com>
Acked-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

lib/kobject_uevent.c

@@ -282,7 +282,7 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 							    kobj_bcast_filter,
 							    kobj);
 			/* ENOBUFS should be handled in userspace */
-			if (retval == -ENOBUFS)
+			if (retval == -ENOBUFS || retval == -ESRCH)
 				retval = 0;
 		} else
 			retval = -ENOMEM;