slimbus: qcom: remove unused variable

This patch fixes below warning when driver is compiled with W=1
qcom-ctrl.c: In function 'qcom_slim_rxwq':
qcom-ctrl.c:442:13: warning: variable 'len' set but not used
 [-Wunused-but-set-variable]

len seems to be unused in this function, so remove it.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/slimbus/qcom-ctrl.c

@@ -439,13 +439,12 @@ static int slim_get_current_rxbuf(struct qcom_slim_ctrl *ctrl, void *buf)
 static void qcom_slim_rxwq(struct work_struct *work)
 {
 	u8 buf[SLIM_MSGQ_BUF_LEN];
-	u8 mc, mt, len;
+	u8 mc, mt;
 	int ret;
 	struct qcom_slim_ctrl *ctrl = container_of(work, struct qcom_slim_ctrl,
 						 wd);
 
 	while ((slim_get_current_rxbuf(ctrl, buf)) != -ENODATA) {
-		len = SLIM_HEADER_GET_RL(buf[0]);
 		mt = SLIM_HEADER_GET_MT(buf[0]);
 		mc = SLIM_HEADER_GET_MC(buf[1]);
 		if (mt == SLIM_MSG_MT_CORE &&