Always pfree tmp WAL key when allocated

We didn't pfree the key in case of `EncryptXLog == true && key == true`

contrib/pg_tde/src/access/pg_tde_xlog_encrypt.c

@@ -206,15 +206,16 @@ TDEXLogSmgrInit(void)
 	{
 		pg_tde_create_wal_key(&EncryptionKey, &GLOBAL_SPACE_RLOCATOR(XLOG_TDE_OID),
 							  TDE_KEY_TYPE_WAL_UNENCRYPTED);
-		pfree(key);
 	}
 	else if (key)
 	{
 		EncryptionKey = *key;
 		pg_atomic_write_u64(&EncryptionState->enc_key_lsn, EncryptionKey.start_lsn);
-		pfree(key);
 	}
 
+	if (key)
+		pfree(key);
+
 	pg_tde_set_db_file_path(GLOBAL_SPACE_RLOCATOR(XLOG_TDE_OID).dbOid, EncryptionState->db_map_path);
 
 #endif