staging: rtl8723bs: Remove rtw_hal_networktype_to_raid()

Change call sites of rtw_hal_networktype_to_raid to instead call
networktype_to_raid_ex as rtw_hal_networktype_to_raid does nothing
except call networktype_to_raid_ex.
Remove now-unused function rtw_hal_networktype_to_raid.
Issue found with Coccinelle.

Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>