HID: sony: Coding style cleanups in sixaxis_set_operational_usb()

Don't mix declaration and allocation, remove some useless newlines
between calling a function and checking its return value.

Signed-off-by: Antonio Ospite <ao2@ao2.it>
Acked-by: Frank Praznik <frank.praznik@oh.rr.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>