fuse: fix node ID type

Node ID is 64bit but it is passed as unsigned long to some functions.  This
breakage wasn't noticed, because libfuse uses unsigned long too.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>