[submodule] Update submodule sonic-linux-kernel to the latest HEAD automatically (#16494)

#### Why I did it
src/sonic-linux-kernel
```
* fa40db7 - (HEAD -> master, origin/master, origin/HEAD) Change the system.map file permission only readable by root (#329) (21 hours ago) [xumia]
```
#### How I did it
#### How to verify it
#### Description for the changelog
This commit is contained in:
mssonicbld 2023-09-08 16:32:40 +08:00 committed by GitHub
parent 7986aba097
commit 084a6e1a3e
No known key found for this signature in database
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@ -1 +1 @@
Subproject commit 7ee50c905dde72ef19f266c9b40951ee5bb76bb0
Subproject commit fa40db7b96f18329fc8b4a56a9295ffd92b139d5