linux-wandboard

ath9k: Fix memleak on TX DMA failure

The driver-specific region has to be freed in case
of a DMA mapping failure.

Cc: stable@kernel.org
Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>