HID: hidraw: tighten ioctl command parsing

The handling for variable-length ioctl commands in hidraw_ioctl() is
rather complex and the check for the data direction is incomplete.

Simplify this code by factoring out the various ioctls grouped by dir
and size, and using a switch() statement with the size masked out, to
ensure the rest of the command is correctly matched.

Fixes: 9188e79e ("HID: add phys and name ioctls to hidraw")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.com>