pstore/platform: fix potential mem leak if pstore_init_fs failed

There is a potential mem leak when pstore_init_fs failed,
since the pstore compression maybe unlikey to initialized
successfully. We must clean up the allocation once this
unlikey issue happens.
Signed-off-by: Nchenqiwu <chenqiwu@xiaomi.com>
Link: https://lore.kernel.org/r/1581068800-13817-1-git-send-email-qiwuchen55@gmail.comSigned-off-by: NKees Cook <keescook@chromium.org>

fs/pstore/platform.c

@@ -823,9 +823,9 @@ static int __init pstore_init(void)
 
 	ret = pstore_init_fs();
 	if (ret)
-		return ret;
+		free_buf_for_compression();
 
-	return 0;
+	return ret;
 }
 late_initcall(pstore_init);