staging: rtl8723bs: remove unused BIT macros definitions

BIT(x) macro used all over the driver is defined in
include/vsdo/bit.h as

	- #define BIT(nr)	(UL(1) << (nr))

which is safer than the local BIT macros declared.
Local macros shift a signed integer which brings
unespected results. For example:

(unsigned long)(1 << 31) => 0xffffffff80000000

shift.c:

int main() {
        printf("%lx\n", (unsigned long)(1 << 31));
        printf("%lx\n", (unsigned long)(1U << 31));
        return 0;
}

...

$ ./shift
ffffffff80000000
80000000

...

So just remove redundant, less safe macro declarations.

Suggested-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Fabio Aiuto <fabioaiuto83@gmail.com>
Link: https://lore.kernel.org/r/20210730134048.8736-1-fabioaiuto83@gmail.com


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