staging: rtl8723bs: Change return type of hal_btcoex_IsBtDisabled()

Change return type of hal_btcoex_IsBtDisabled from u8 to bool as the
only possible return values are true and false.
Where needed, modify accordingly the type of the variables used to store
this return value.

Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
Link: https://lore.kernel.org/r/20190702070132.6997-9-nishkadg.linux@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>