board: fsl_validate: Fix Double free Issue

Remove Double free issue from calc_img_key_hash() and
calc_esbchdr_esbc_hash() function.
Verified the secure boot changes using lx2162aqds board.

Signed-off-by: Kshitiz Varshney <kshitiz.varshney@nxp.com>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>
diff --git a/board/freescale/common/fsl_validate.c b/board/freescale/common/fsl_validate.c
index c90afe2..34875d0 100644
--- a/board/freescale/common/fsl_validate.c
+++ b/board/freescale/common/fsl_validate.c
@@ -499,12 +499,8 @@
 		return ret;
 
 	ret = algo->hash_init(algo, &ctx);
-	if (ret) {
-		if (ctx)
-			free(ctx);
+	if (ret)
 		return ret;
-	}
-
 	/* Update hash for ESBC key */
 #ifdef CONFIG_KEY_REVOCATION
 	if (check_srk(img)) {
@@ -519,15 +515,12 @@
 			img->img_key, img->key_len, 1);
 	if (ret)
 		return ret;
-
 	/* Copy hash at destination buffer */
 	ret = algo->hash_finish(algo, ctx, hash_val, algo->digest_size);
 	if (ret) {
-		if (ctx)
-			free(ctx);
+		free(ctx);
 		return ret;
 	}
-
 	for (i = 0; i < SHA256_BYTES; i++)
 		img->img_key_hash[i] = hash_val[i];
 
@@ -554,18 +547,14 @@
 
 	ret = algo->hash_init(algo, &ctx);
 	/* Copy hash at destination buffer */
-	if (ret) {
-		free(ctx);
+	if (ret)
 		return ret;
-	}
 
 	/* Update hash for CSF Header */
 	ret = algo->hash_update(algo, ctx,
 		(u8 *)&img->hdr, sizeof(struct fsl_secboot_img_hdr), 0);
-	if (ret) {
-		free(ctx);
+	if (ret)
 		return ret;
-	}
 
 	/* Update the hash with that of srk table if srk flag is 1
 	 * If IE Table is selected, key is not added in the hash
@@ -592,22 +581,17 @@
 		key_hash = 1;
 	}
 #endif
-	if (ret) {
-		free(ctx);
+	if (ret)
 		return ret;
-	}
 	if (!key_hash) {
 		free(ctx);
 		return ERROR_KEY_TABLE_NOT_FOUND;
 	}
-
 	/* Update hash for actual Image */
 	ret = algo->hash_update(algo, ctx,
 		(u8 *)(*(img->img_addr_ptr)), img->img_size, 1);
-	if (ret) {
-		free(ctx);
+	if (ret)
 		return ret;
-	}
 
 	/* Copy hash at destination buffer */
 	ret = algo->hash_finish(algo, ctx, hash_val, algo->digest_size);