if_bridge: unused 'disable' parameter in bridge_stop()

Hello,

I was tracing the if_bridge driver on the current main branch and noticed
that the bridge_stop method takes in an 'int disable' parameter that
doesn't seem to be used in the function itself.

Currently, there are two calls to bridge_stop() in the driver:
1. In bridge_clone_destroy() - Line 940
2. In bridge_ioctl() - Line 1073
In both of these calls, the disable parameter is hard-coded to 1.
There doesn't seem to be any case where 0 is used for the parameter.

Since the ifnet structure doesn't require a stop function, I assume this is
purely for the bridge itself.

Is this parameter still relevant/needed in the driver architecture? If not,
I'd be happy to make a small pr to update this.

I'm still finding my footing around the FreeBSD network stack so please let
me know if this parameter has a purpose I overlooked.

Best,
Aaron