common: Add NULL checks for malloc_cache_aligned in autoboot.c

- Check return value of malloc_cache_aligned for presskey and sha.
- Return -ENOMEM if memory allocation fails.
- Free allocated memory in error paths."

Triggers found by static analyzer Svace.

Signed-off-by: Anton Moryakov <ant.v.moryakov@gmail.com>

common/autoboot.c

@@ -186,10 +186,15 @@ static int passwd_abort_sha256(uint64_t etime)
 	ret = hash_parse_string(algo_name, sha_env_str, sha_env);
 	if (ret) {
 		printf("Hash %s not supported!\n", algo_name);
+		free(presskey);
 		return 0;
 	}
 
 	sha = malloc_cache_aligned(SHA256_SUM_LEN);
+	if (!sha) {
+		free(presskey);
+		return -ENOMEM;
+	}
 	size = SHA256_SUM_LEN;
 	/*
 	 * We don't know how long the stop-string is, so we need to