smb3: add missing read completion trace point

When ENODATA returned we weren't logging the read completion
(not an error, but can be indicated by logging length 0) which
makes looking at read traces confusing for smb3.
Signed-off-by: NSteve French <stfrench@microsoft.com>
Reviewed-by: NRonnie Sahlberg <lsahlber@redhat.com>

fs/cifs/smb2pdu.c

@@ -3404,7 +3404,10 @@ SMB2_read(const unsigned int xid, struct cifs_io_parms *io_parms,
 					    io_parms->tcon->tid, ses->Suid,
 					    io_parms->offset, io_parms->length,
 					    rc);
-		}
+		} else
+			trace_smb3_read_done(xid, req->PersistentFileId,
+				    io_parms->tcon->tid, ses->Suid,
+				    io_parms->offset, 0);
 		free_rsp_buf(resp_buftype, rsp_iov.iov_base);
 		return rc == -ENODATA ? 0 : rc;
 	} else