rsi: correct SDIO disconnect path handling

Sometimes it's observed that we get interrupt/Rx frame when device is
already detached from mac80211. In this case couple of error messages
are displayed in dmesg log. This patch corrects the order so that
disconnection will happen cleanly

Signed-off-by: Karun Eagalapati <karun256@gmail.com>
Signed-off-by: Amitkumar Karwar <amit.karwar@redpinesignals.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>