mwifiex: fix checkpatch --strict warnings/errors Part 9

For files sta_rx.c, sta_tx.c, txrx.c, util.c and wmm.c

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