bfin_5xx: misplaced parentheses

`!' has a higher precedence than `&', parentheses are misplaced.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Sonic Zhang <sonic.zhang@analog.com>
Cc: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>