net/if_media.c: avoid if_bge attach panic on Supermicro H13SSL-N

[mm]

Summary

Exit on SIOCGIFMEDIA/SIOCGIFXMEDIA if ifm_status is unpopulated.

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=277849

[kib]

This is indeed a workaround, I remember fixing something similar for ports' variant of if_re. The fix was to move the ether_ifattach() after the media structures are initialized,
https://github.com/alexdupre/rtl_bsd_drv/commit/2a97cc982d0362b69040d1c849f697ff61e37106

I did not looked at the bge code to confirm that it is the case.

[zlei]

In D47314#1079145, @kib wrote:

This is indeed a workaround, I remember fixing something similar for ports' variant of if_re. The fix was to move the ether_ifattach() after the media structures are initialized,
https://github.com/alexdupre/rtl_bsd_drv/commit/2a97cc982d0362b69040d1c849f697ff61e37106

I did not looked at the bge code to confirm that it is the case.

I checked the source code of if_gbe, it appears that the media structures are initialized correctly.
It is better dig into the core dump to inspect what's going on.