crypto: xilinx: Handle AES PM API return status

Return value of AES PM API is not handled which may result in
unexpected value of "status" in zynqmp_pm_aes_engine().

Consider "status" value as valid only if AES PM API is successful.

Fixes: bc86f9c546 ("firmware: xilinx: Remove eemi ops for aes engine")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Link: https://lore.kernel.org/r/1588330354-27942-1-git-send-email-rajan.vaja@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/crypto/xilinx/zynqmp-aes-gcm.c

@@ -85,6 +85,7 @@ static int zynqmp_aes_aead_cipher(struct aead_request *req)
 	dma_addr_t dma_addr_data, dma_addr_hw_req;
 	unsigned int data_size;
 	unsigned int status;
+	int ret;
 	size_t dma_size;
 	char *kbuf;
 	int err;
@@ -132,9 +133,12 @@ static int zynqmp_aes_aead_cipher(struct aead_request *req)
 		hwreq->key = 0;
 	}
 
-	zynqmp_pm_aes_engine(dma_addr_hw_req, &status);
+	ret = zynqmp_pm_aes_engine(dma_addr_hw_req, &status);
 
-	if (status) {
+	if (ret) {
+		dev_err(dev, "ERROR: AES PM API failed\n");
+		err = ret;
+	} else if (status) {
 		switch (status) {
 		case ZYNQMP_AES_GCM_TAG_MISMATCH_ERR:
 			dev_err(dev, "ERROR: Gcm Tag mismatch\n");