Make assignments to "net.inet.tcp.cc.algorithm" work by fixing a bad
string comparison.

MFC after:	3 days
Reported by:	Jukka Ukkonen <jau789@gmail.com>
Sponsored by:	Mellanox Technologies
bin/dd: Fix incorrect casting of arguments

dd(1) casts many of its numeric arguments from uintmax_t to intmax_t
and back again to detect whether or not the original arguments were
negative. This caused wrong behaviour in some boundary cases:

$ dd if=/dev/zero of=/dev/null count=18446744073709551615
dd: count cannot be negative

After the fix:

$ dd if=/dev/zero of=/dev/null count=18446744073709551615
dd: count: Result too large

PR:		191263
Submitted by:	will@worrbase.com
Approved by:	cognet@
Clarify the documentation of pmcstat:
the -d argument should be passed before -p, -s, -P or -S to be taken in account

Differential Revision:	https://reviews.freebsd.org/D1011
Reviewed by:	adrian, gnn
MFC after:	1 week
Correct a typo: this is the manpage for pthread_cleanup_pop, not push.

Submitted by:	ian
Fix rendering

Submitted by:	brueffer
Preserve limitation of "TCP_CA_NAME_MAX" when matching the algorithm
name.

MFC after:	3 days
Suggested by:	gnn @
Tiny comment fixup.
Do not automatically install routes to link-local and interface-local multicast
addresses.

Obtained from:	Yandex LLC
Sponsored by:	Yandex LLC
Merge remote-tracking branch 'freebsd/master' into hardened/current/master
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/userlandenhanced