staging: r8723au: Fix sparse warnings in core/rtw_ap.c

The following warnings are fixed:

drivers/staging/rtl8723au/core/rtw_ap.c:79:23: warning: incorrect type in assignment (different base types)
drivers/staging/rtl8723au/core/rtw_ap.c:79:23:    expected unsigned short [unsigned] [usertype] tim_bitmap_le
drivers/staging/rtl8723au/core/rtw_ap.c:79:23:    got restricted __le16 [usertype] <noident>
drivers/staging/rtl8723au/core/rtw_ap.c:1441:37: warning: restricted __le16 degrades to integer

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>