rtw89: mac: correct decision on error status by scenario

The raw error code might combine error scenario and error status.
But, the error scenario isn't parsed previously. It makes us mishandle
cpu exception and assertion. Now, we correct the error status for them.

Besides, a few uses of error status are refined.

Signed-off-by: Zong-Zhe Yang <kevin_yang@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220314071250.40292-4-pkshih@realtek.com