Input: sur40 - suppress false uninitialized variable warning

We will never use packet_id before initializing it as we start with
"need_blobs == -1" and will set packet_id there.

Also use le32_to_cpu when fetching header->packet_id.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --cc drivers/input/touchscreen/sur40.c
Simple merge