fuse: Fix compilation on L

Change-Id: I7c989dea0f0b270535da089b0e5a9eafb17cae96
Changed off_t to loff_t

- off_t is long, loff_t is long long (32bit vs. 64bit)
- loff_t required by exfat at least so fuse needs to have it also

Change-Id: I76a4e4cc1af9b85cd0bed2bb220723e959b1a04f