mwl8k: correct/silence sparse warnings

drivers/net/wireless/mwl8k.c:1541:21: warning: incorrect type in assignment (different base types)
drivers/net/wireless/mwl8k.c:1541:21:    expected restricted __le16 [usertype] result
drivers/net/wireless/mwl8k.c:1541:21:    got int
drivers/net/wireless/mwl8k.c:1575:42:    expected unsigned short [unsigned] [usertype] cmd
drivers/net/wireless/mwl8k.c:1575:42:    got restricted __le16 [usertype] code
drivers/net/wireless/mwl8k.c:1587:50: warning: incorrect type in argument 1 (different base types)
drivers/net/wireless/mwl8k.c:1587:50:    expected unsigned short [unsigned] [usertype] cmd
drivers/net/wireless/mwl8k.c:1587:50:    got restricted __le16 [usertype] code
drivers/net/wireless/mwl8k.c:1592:50: warning: incorrect type in argument 1 (different base types)
drivers/net/wireless/mwl8k.c:1592:50:    expected unsigned short [unsigned] [usertype] cmd
drivers/net/wireless/mwl8k.c:1592:50:    got restricted __le16 [usertype] code
drivers/net/wireless/mwl8k.c:1845:27: warning: incorrect type in argument 1 (different base types)
drivers/net/wireless/mwl8k.c:1845:27:    expected unsigned int [unsigned] [usertype] <noident>
drivers/net/wireless/mwl8k.c:1845:27:    got restricted __le32 [usertype] <noident>
drivers/net/wireless/mwl8k.c:1848:27: warning: incorrect type in argument 1 (different base types)
drivers/net/wireless/mwl8k.c:1848:27:    expected unsigned int [unsigned] [usertype] <noident>
drivers/net/wireless/mwl8k.c:1848:27:    got restricted __le32 [usertype] <noident>
drivers/net/wireless/mwl8k.c:1851:27: warning: incorrect type in argument 1 (different base types)
drivers/net/wireless/mwl8k.c:1851:27:    expected unsigned int [unsigned] [usertype] <noident>
drivers/net/wireless/mwl8k.c:1851:27:    got restricted __le32 [usertype] <noident>
drivers/net/wireless/mwl8k.c:1854:27: warning: incorrect type in argument 1 (different base types)
drivers/net/wireless/mwl8k.c:1854:27:    expected unsigned int [unsigned] [usertype] <noident>
drivers/net/wireless/mwl8k.c:1854:27:    got restricted __le32 [usertype] <noident>
drivers/net/wireless/mwl8k.c:1857:27: warning: incorrect type in argument 1 (different base types)
drivers/net/wireless/mwl8k.c:1857:27:    expected unsigned int [unsigned] [usertype] <noident>
drivers/net/wireless/mwl8k.c:1857:27:    got restricted __le32 [usertype] <noident>
drivers/net/wireless/mwl8k.c:1860:27: warning: incorrect type in argument 1 (different base types)
drivers/net/wireless/mwl8k.c:1860:27:    expected unsigned int [unsigned] [usertype] <noident>
drivers/net/wireless/mwl8k.c:1860:27:    got restricted __le32 [usertype] <noident>
drivers/net/wireless/mwl8k.c:3055:20: warning: incorrect type in assignment (different base types)
drivers/net/wireless/mwl8k.c:3055:20:    expected restricted __le16 [usertype] ht_caps
drivers/net/wireless/mwl8k.c:3055:20:    got unsigned short [unsigned] [usertype] cap

At least the last one looks like a real bug...

Signed-off-by: John W. Linville <linville@tuxdriver.com>
Acked-by: Lennert Buytenhek <buytenh@wantstofly.org>