[rdk-b][mt7986][wifi-hal][Fix wrong sprintf format]

[Description]
Fix wrong sprintf format in SSIDTrafficStats2 function.
It would cause error when Wi-Fi agent fill TR181 data model.

[Release-log]
N/A

Change-Id: I6dd523ed0d9d9132d20c03e4068f049d993d697b
1 file changed