KVM: x86: fix typo "notifer"

KVM: x86: fix typo "notifer"

Patch series "treewide: Fix typo "notifer"", v3.

There are some spelling mistakes of 'notifer' in comments which
should be 'notifier'.

Fix them and add it to scripts/spelling.txt.

This patch (of 8):

There are some spelling mistakes of 'notifer' which should be 'notifier'.

Link: https://lkml.kernel.org/r/576F0D85F6853074+20250722072734.19367-1-wangyuli@uniontech.com
Link: https://lkml.kernel.org/r/7F05778C3A1A9F8B+20250722073431.21983-1-wangyuli@uniontech.com
Signed-off-by: WangYuli <wangyuli@uniontech.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>