Make autofs timeout handling use timeout task instead of callout;
that's because the handler can sleep on sx lock.

Reviewed by:	kib
MFC after:	1 week
Sponsored by:	The FreeBSD Foundation
Fix the checksum computation for UDPLite/IPv6. This requires the
usage of a function computing the checksum only over a part of the function.
Therefore introduce in6_cksum_partial() and implement in6_cksum() based
on that.
While there, ensure that the UDPLite packet contains at least enough bytes
to contain the header.

Reviewed by: kevlo
MFC after: 3 days
Call uma_zfree() outside of lock, and improve comment.

Sponsored by:	The FreeBSD Foundation
Make disconnected LUN 0 don't remain in half-configured state if there are
no LUNs on SPC-3 target after we tried REPORT LUNS.