Revert "kernel/sysctl: fix: 'warning: 'kbuf' may be used uninitialized in this function' #2"

This reverts commit 2f26afbab9f38cd33d04407dc51212911fe16ede.
kernel/sysctl: fix: 'warning: 'kbuf' may be used uninitialized in this function' #2

Signed-off-by: Lens-F <tnoah12@gmail.com>

Authored: Dennis Rassmann <showp1984@gmail.com>