linux-wandboard

libertas: don't use dynamic-sized array

sparse complains about a bad constant expression due to the use of a
dynamic-sized array in get_common_rates().  Allocate and free the array
instead.

Signed-off-by: Andrey Yurovsky <andrey@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>