crypto/fsl: Clear the memory when blob decapsulation fails

issue: blob decapsulation operation store the decrypted data
       in memory even if ICV check failed.

fix: clear the blob data output memory.

Fixes: c5de15cbc8 (crypto/fsl: Add command for encapsulating/decapsulating blobs)
Signed-off-by: Gaurav Jain <gaurav.jain@nxp.com>
Reviewed-by: Kshitiz Varshney <kshitiz.varshney@nxp.com>
Tested-by: Kshitiz Varshney <kshitiz.varshney@nxp.com>
Reviewed-by: Fabio Estevam <festevam@denx.de>
diff --git a/drivers/crypto/fsl/fsl_blob.c b/drivers/crypto/fsl/fsl_blob.c
index e8202cc..9b6e4bc 100644
--- a/drivers/crypto/fsl/fsl_blob.c
+++ b/drivers/crypto/fsl/fsl_blob.c
@@ -71,6 +71,10 @@
 	ret = run_descriptor_jr(desc);
 
 	if (ret) {
+		/* clear the blob data output buffer */
+		memset(dst, 0x00, len);
+		size = ALIGN(len, ARCH_DMA_MINALIGN);
+		flush_dcache_range((unsigned long)dst, (unsigned long)dst + size);
 		printf("Error in blob decapsulation: %d\n", ret);
 	} else {
 		size = ALIGN(len, ARCH_DMA_MINALIGN);