util/filemonitor-inotify.c: spelling fix: kenel
Fixes: 2e12dd405c66 "util/filemonitor-inotify: qemu_file_monitor_watch(): assert no overflow"
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>