cient/fuse_ll.c: align fuse_ll_forget() with fuse3 API

cient/fuse_ll.c: align fuse_ll_forget() with fuse3 API

In fuse2 forget() is defined as:

void (*forget) (fuse_req_t req, fuse_ino_t ino, unsigned long nlookup);

In fuse3 forget() is defined as:

void (*forget) (fuse_req_t req, fuse_ino_t ino, uint64_t nlookup);

Apparently FUSE fixed the issue of nlookup becoming 32 bit value on 32 bit systems as nlookup should be 64 bit value at all times.

We should use new function signature to avoid compilation failure in 32 bit mode with fuse3.

Signed-off-by: Vladimir Bashkirtsev <vladimir@bashkirtsev.com>