[PATCH] input: fix ucb1x00-ts breakage after conversion to dynamic input_dev allocation

The bd622663 commit broke the UCB1x00
touchscreen driver since the idev structure was assumed to be into the ts
structure, simply casting the former to the later in a couple places.

This patch fixes those, and also cache the idev pointer between multiple
calls to input_report_abs() to avoid growing the compiled code needlessly.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Cc: Dmitry Torokhov <dtor_core@ameritech.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>