Defined the (*ioctl)() commands as unsigned int (#381)

Defined the (*ioctl)() commands as unsigned int (#381)

Instead of the Posix ioctl(2) command, Linux uses its own variant of ioctl()
in which the commands are requested as "unsigned long" and truncated to
32 bits by the fuse kernel module. Transmitting the commands to user space
file systems as "unsigned int" is a workaround for processing ioctl()
commands which do not fit into a signed int.