DMA: PL330: Fix potential NULL pointer dereference in pl330_submit_req()

'r->cfg' is being checked for NULL. However, it is dereferenced
in the previous statements. Thus moving those statements within
the check.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Jassi Brar <jassisinghbrar@gmail.com>
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>

drivers/dma/pl330.c

@@ -1567,17 +1567,19 @@ static int pl330_submit_req(void *ch_id, struct pl330_req *r)
 		goto xfer_exit;
 	}
 
-	/* Prefer Secure Channel */
-	if (!_manager_ns(thrd))
-		r->cfg->nonsecure = 0;
-	else
-		r->cfg->nonsecure = 1;
 
 	/* Use last settings, if not provided */
-	if (r->cfg)
+	if (r->cfg) {
+		/* Prefer Secure Channel */
+		if (!_manager_ns(thrd))
+			r->cfg->nonsecure = 0;
+		else
+			r->cfg->nonsecure = 1;
+
 		ccr = _prepare_ccr(r->cfg);
-	else
+	} else {
 		ccr = readl(regs + CC(thrd->id));
+	}
 
 	/* If this req doesn't have valid xfer settings */
 	if (!_is_valid(ccr)) {