wifi: rtw89: use readable return 0 in rtw89_mac_cfg_ppdu_status()

For normal (successful) flow, it must return 0. The original code uses
'return ret', and then we need to backward reference to initial value to
know 'ret = 0'. Changing them to 'return 0', because it will be more
readable and intuitive. This patch doesn't change logic at all.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/r/202302101023.ctlih5q0-lkp@intel.com/


Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230213091328.25481-1-pkshih@realtek.com