[media] dib9000: release a lock on error

This lock should be released as well on the error path.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Patrick Boettcher <Patrick.Boettcher@dibcom.fr>
Cc: Olivier Grenie <olivier.grenie@dibcom.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/dvb/frontends/dib9000.c

@@ -2169,6 +2169,7 @@ static int dib9000_read_ber(struct dvb_frontend *fe, u32 * ber)
 	DibAcquireLock(&state->demod_lock);
 	DibAcquireLock(&state->platform.risc.mem_mbx_lock);
 	if (dib9000_fw_memmbx_sync(state, FE_SYNC_CHANNEL) < 0) {
+		DibReleaseLock(&state->platform.risc.mem_mbx_lock);
 		ret = -EIO;
 		goto error;
 	}