LU-12678 lnet: remove locking protection ln_testprotocompat

LU-12678 lnet: remove locking protection ln_testprotocompat

lnet_net_lock(LNET_LOCK_EX) is a heavy-weight lock that is not
necessary here.  The bits in this field are only set rarely - via an
ioctl - and the pattern for reading and clearing them exactly
matches test_and_clear_bit().  So change the field to "unsigned
long" (so test_and_clear_bit() can be used), and use
test_and_clear_bit(), discarding all other locking.

Test-Parameters: trivial testlist=sanity-lnet
Signed-off-by: Mr NeilBrown <neilb@suse.de>
Change-Id: Ie420fcb3d547d9ec04025b921d5b24bd8f2fcce3
Reviewed-on: https://review.whamcloud.com/36856
Reviewed-by: Alexey Lyashkov <c17817@cray.com>
Reviewed-by: Chris Horn <hornc@cray.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Oleg Drokin <green@whamcloud.com>