staging: rtl8192u: ieee80211: Fix sparse endianness warnings

Fix the following sparse warnings:

drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c:663:32: warning: incorrect type in assignment (different base types)
drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c:663:32:    expected restricted __le16 [usertype] frame_ctl
drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c:663:32:    got int
drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c:664:50: warning: invalid assignment: |=
drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c:664:50:    left side has type restricted __le16
drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c:664:50:    right side has type int

Signed-off-by: Gaston Gonzalez <gascoar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>