MFC r210044, r214622:

MFC r210044, r214622:

MFC r210044 (pjd):
MFp4 180933:

Initialize rw_count properly so that zdb(8) doesn't trigger assertion in
rw_enter():

	ASSERT(rwlp->rw_count == 0);

While here, assert that rw_count is 0 when destroying the lock.

MFC r214622 (pjd):
1. Remove invalid assertion.
2. Properly recalculate delta in case pthread_cond_timedwait() is interrupted.
3. Style fix.

Reported by:	[1] App Deb <appdebgr@gmail.com>

Approved by:	re (kib), pjd, delphij (mentor)

git-svn-id: svn://svn.freebsd.org/base/stable/8@216434 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f