Corpus for mknodat$null:

Coverage	Program
1869	syz_mount_image$tmpfs-inotify_init-inotify_add_watch-inotify_rm_watch-mknodat$null
1430	prctl$PR_SET_SYSCALL_USER_DISPATCH_ON-syz_mount_image$tmpfs-mknodat$null-fchownat
1106	syz_mount_image$tmpfs-socket$nl_xfrm-getsockopt$sock_cred-setuid-mknodat$null
422	syz_open_procfs-mknodat$null