[PATCH] libertas: region code values specified as 8bit

This patch strips away possible mess in regioncode (eg. on my card - 88W8305
chipset - I get 0x3031 instead of expected 0x0031 and as a result the driver
defaults to USA region which is obviously incorrect). Following patch fixes
the issue.

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>