This fixes the following error
```
admin@sonic:~$ sudo fwutil show status
mount: /mnt/onie-fs: special device /dev/sda2
does not exist.
Error: Command '['mount', '-n', '-r', '-t', 'ext4', '/dev/sda2\n', '/mnt/onie-fs']' returned non-zero exit status 32.. Aborting...
Aborted!
admin@sonic:~$ sudo vi /usr/local/lib/python3.9/dist-packages/sonic_platform/
```
Seems like #11877 the rstrip('\n') was removed. Probably by mistake.
Signed-off-by: Stephen Sun <stephens@nvidia.com>
8c73e68468