drivers/net/wireless/ath/ath9k/ar9003_mac.c: removes unnecessary semicolon

removes unnecessary semicolon

Found by Coccinelle: http://coccinelle.lip6.fr/



Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>