account per-file, dentry, and inode data

blockdev/superblock and temporary per-request data was left alone, as
this usually isn't accounted
Reviewed-by: NShakeel Butt <shakeelb@google.com>
Signed-off-by: NKhazhismel Kumykov <khazhy@google.com>
Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>