pw: fix up deletion of users from groups

Previuosly given 'foo,bar' members, removing 'foo' would result in an
infinite loop.

PR:		191427
Submitted by:	Voradesh Yenbut <yenbut cs.washington.edu>
MFC after:	1 week
Simplify the code a little bit using the update_sensor_sysctl() routine to
retrieve the sensor temperature.

This also avoid the overflow that could happen on sysctlnametomib(3)
because the code was not checking the length of the mib array.

CID:		1222504
Add missing variable declarations when using RSS.

Reported by: bryanv@
Add CTLFLAG_NOFETCH flag; console vty code runs before tunable fetch

Also remove redundant "" assignment for string in BSS.

Submitted by:	hselasky@