HID: uhid: forward create_req to create2_req

Instead of hard-coding the uhid_dev_create() function twice, copy any
create_req into a create2_req structure and forward it.

We allocate uhid_create_req on the stack here, but that should be fine.
Unlike uhid_create2_req it is fairly small (<1KB) and it's only used
temporarily to swap entries. uhid_dev_create2() doesn't access it.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>