HID: hid-core: optimize in case of hidraw

When using hidraw, hid buffer can be big and take lot's of
time to process (interrupt) kernel context.
Don't try to parse report if we are only interrested in hidraw.

Also don't prepare data for debug stuff if no debugfs file
are opened.

Signed-off-by: Matthieu CASTET <matthieu.castet@parrot.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>