patch as-lock-macro-simplification

*** 5651,5661 ****
           * block on a_lock here because this waiting writer will prevent
           * further readers like ufs_read from progressing and could cause
           * deadlock between ufs_read/ufs_map/pagefault when a quiesce is
           * pending.
           */
!         while (!AS_LOCK_TRYENTER(as, &as->a_lock, RW_WRITER)) {
                  ufs_map_alock_retry_cnt++;
                  delay(RETRY_LOCK_DELAY);
          }
  
          /*
--- 5651,5661 ----
           * block on a_lock here because this waiting writer will prevent
           * further readers like ufs_read from progressing and could cause
           * deadlock between ufs_read/ufs_map/pagefault when a quiesce is
           * pending.
           */
!         while (!AS_LOCK_TRYENTER(as, RW_WRITER)) {
                  ufs_map_alock_retry_cnt++;
                  delay(RETRY_LOCK_DELAY);
          }
  
          /*
*** 5667,5677 ****
                  /*
                   * ufs_lockfs_trybegin() did not succeed. It is safer to give up
                   * as->a_lock and wait for ulp->ul_fs_lock status to change.
                   */
                  ufs_map_lockfs_retry_cnt++;
!                 AS_LOCK_EXIT(as, &as->a_lock);
                  as_rangeunlock(as);
                  if (error == EIO)
                          goto out;
  
                  mutex_enter(&ulp->ul_lock);
--- 5667,5677 ----
                  /*
                   * ufs_lockfs_trybegin() did not succeed. It is safer to give up
                   * as->a_lock and wait for ulp->ul_fs_lock status to change.
                   */
                  ufs_map_lockfs_retry_cnt++;
!                 AS_LOCK_EXIT(as);
                  as_rangeunlock(as);
                  if (error == EIO)
                          goto out;
  
                  mutex_enter(&ulp->ul_lock);