LU-7099 lnet: lock improvement for ko2iblnd

LU-7099 lnet: lock improvement for ko2iblnd

kiblnd_check_sends() takes conn::ibc_lock at the begin and release
this lock at the end, this is inefficient because most use-case
needs to explicitly release ibc_lock before caling this function.

This patches changes it to kiblnd_check_sends_locked() and avoid
unnecessary lock dances.

Test-Parameters: trivial

Signed-off-by: Doug Oucharek <doug.s.oucharek@intel.com>
Change-Id: I3b348029dace70fd27beafa495f7a9e0bde442ed
Reviewed-on: http://review.whamcloud.com/20322
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Amir Shehata <amir.shehata@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>