Drivers:net:wireless:ti:wl1251: Fixed Sparse invalid assignment warning

Sparse warns about invalid assignment in
drivers/net/wireless/ti/wl1251/cmd.c:451:42: warning: invalid assignment: |=
drivers/net/wireless/ti/wl1251/cmd.c:451:42:    left side has type restricted __le16
drivers/net/wireless/ti/wl1251/cmd.c:451:42:    right side has type int
Hence type converted right side to __le16.

Signed-off-by: Surendra Patil <surendra.tux@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>