block: remove __blk_put_request()

Now there's no difference between blk_put_request() and
__blk_put_request() anymore, get rid of the underscore version and
convert the few callers.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/scsi/st.c

@@ -530,7 +530,7 @@ static void st_scsi_execute_end(struct request *req, blk_status_t status)
 		complete(SRpnt->waiting);
 
 	blk_rq_unmap_user(tmp);
-	__blk_put_request(req->q, req);
+	blk_put_request(req);
 }
 
 static int st_scsi_execute(struct st_request *SRpnt, const unsigned char *cmd,