mwl8k: Fix checkpatch.pl and sparse warnings and errors

Fix checkpatch errors and warnings comprising of indent errors, spaces and
__packed warnings. Also fix 'make C = 2' warnings.

Signed-off-by: Yogesh Ashok Powar <yogeshp@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>