selinux: reduce the number of calls to synchronize_net() when flushing caches

When flushing the AVC, such as during a policy load, the various
network caches are also flushed, with each making a call to
synchronize_net() which has shown to be expensive in some cases.
This patch consolidates the network cache flushes into a single AVC
callback which only calls synchronize_net() once for each AVC cache
flush.

Reported-by: Jaejyn Shin <flagon22bass@gmail.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>

diff --cc security/selinux/hooks.c
Simple merge

diff --cc security/selinux/include/netif.h
Simple merge

diff --cc security/selinux/include/netnode.h
Simple merge

diff --cc security/selinux/include/netport.h
Simple merge

diff --cc security/selinux/netif.c
Simple merge

diff --cc security/selinux/netnode.c
Simple merge

diff --cc security/selinux/netport.c
Simple merge