IB/hfi1: Use non-atomic __test_and_clear_bit in hot path

qp->r_aflags is already protected by qp->r_lock, therefore,
test_and_clear_bit() doesn't need to be atomic. Profile
shows this function call is costly.

Change the test_and_clear_bit() call to use the non-atomic
variant.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Sebastian Sanchez <sebastian.sanchez@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>