arm64: zynqmp: Check return value in zynqmp_mmio_rawwrite()

There should be return value check from zynqmp_mmio_read() in
zynqmp_mmio_rawwrite() to make sure that errors are propagated properly.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/arch/arm/cpu/armv8/zynqmp/cpu.c b/arch/arm/cpu/armv8/zynqmp/cpu.c
index e122be5..1279dc8 100644
--- a/arch/arm/cpu/armv8/zynqmp/cpu.c
+++ b/arch/arm/cpu/armv8/zynqmp/cpu.c
@@ -212,8 +212,12 @@
 {
 	u32 data;
 	u32 value_local = value;
+	int ret;
+
+	ret = zynqmp_mmio_read(address, &data);
+	if (ret)
+		return ret;
 
-	zynqmp_mmio_read(address, &data);
 	data &= ~mask;
 	value_local &= mask;
 	value_local |= data;