nl80211: Fix simultaneous scanning failure in case of MLO

nl80211: Fix simultaneous scanning failure in case of MLO

Currently only one scan can be performed on per phy level at a time in
the driver. Due to this, if another scan request is sent via anoother
underlying phy, the kernel returns -EBUSY. This would result in hostapd
trying to set the interface into station mode if it was originally in AP
mode and retry sending a scan request. However, this behavior is
expected in case of multi link operation and hence there is no need to
switch the mode as such.

Hence, add logic to not change the NL mode if the kernel returns -EBUSY
during multi link AP operation. The caller can accordingly decide and,
if needed, it can re-schedule a scan request after some time.

Signed-off-by: Aditya Kumar Singh <quic_adisi@quicinc.com>