wifi: mt76: scan: Fix 'mlink' dereferenced before IS_ERR_OR_NULL check

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202504011739.HvUKtUUe-lkp@intel.com/


Fixes: 3ba20af8 ("wifi: mt76: scan: set vif offchannel link for scanning/roc")
Signed-off-by: Feng Jiang <jiangfeng@kylinos.cn>
Link: https://patch.msgid.link/20250402062415.25434-1-jiangfeng@kylinos.cn


Signed-off-by: Felix Fietkau <nbd@nbd.name>