smb: client: change smbd_deregister_mr() to return void

No callers checks the return value and this makes further
changes easier.

Cc: Steve French <[e-mail]>
Cc: Tom Talpey <[e-mail]>
Cc: Long Li <[e-mail]>
Cc: Namjae Jeon <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Signed-off-by: Stefan Metzmacher <[e-mail]>
Signed-off-by: Steve French <[e-mail]>

fs/smb/client/smbdirect.c

···
  * and we have to locally invalidate the buffer to prevent data is being
  * modified by remote peer after upper layer consumes it
  */
-int smbd_deregister_mr(struct smbdirect_mr_io *smbdirect_mr)
+void smbd_deregister_mr(struct smbdirect_mr_io *smbdirect_mr)
 {
 	struct ib_send_wr *wr;
 	struct smbdirect_socket *sc = smbdirect_mr->socket;
···
 done:
 	if (atomic_dec_and_test(&sc->mr_io.used.count))
 		wake_up(&sc->mr_io.cleanup.wait_queue);
-
-	return rc;
 }
 
 static bool smb_set_sge(struct smb_extract_to_rdma *rdma,

fs/smb/client/smbdirect.h

···
 struct smbdirect_mr_io *smbd_register_mr(
 	struct smbd_connection *info, struct iov_iter *iter,
 	bool writing, bool need_invalidate);
-int smbd_deregister_mr(struct smbdirect_mr_io *mr);
+void smbd_deregister_mr(struct smbdirect_mr_io *mr);
 
 #else
 #define cifs_rdma_enabled(server)	0