ecryptfs: Fix memory leakage in keystore.c

In 'decrypt_pki_encrypted_session_key' function:

Initializes 'payload' pointer and releases it on exit.

Signed-off-by: Geyslan G. Bem <[e-mail]>
Signed-off-by: Tyler Hicks <[e-mail]>
Cc: [e-mail] # v2.6.28+

fs/ecryptfs/keystore.c

···
 	struct ecryptfs_msg_ctx *msg_ctx;
 	struct ecryptfs_message *msg = NULL;
 	char *auth_tok_sig;
-	char *payload;
+	char *payload = NULL;
 	size_t payload_len = 0;
 	int rc;
 
···
 	}
 out:
 	kfree(msg);
+	kfree(payload);
 	return rc;
 }