rsi: Clean up loop in the interrupt handler

rsi: Clean up loop in the interrupt handler

The inner do { ... } while loop is completely useless, all it does
is iterate over a switch-case statement, one bit at a time. This
can easily be replaced by simple if (status & bit) { ... } tests
for each bit. No functional change.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Angus Ainslie <angus@akkea.ca>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Martin Kepplinger <martink@posteo.de>
Cc: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@puri.sm>
Cc: Siva Rebbagondla <siva8118@gmail.com>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20201103180941.443528-2-marex@denx.de