Rewrite linux_ifconf() to be more like ifconf() in net/if.c so that we do not call uiomove() while IFNET_RLOCK() is held. This eliminates the witness warning:
Rewrite linux_ifconf() to be more like ifconf() in net/if.c
so that we do not call uiomove() while IFNET_RLOCK() is held.
This eliminates the witness warning:

Calling uiomove() with the following non-sleepable locks held:
exclusive sleep mutex ifnet r = 0 (0xc096dd60) locked @
/usr/src/sys/modules/linux/../../compat/linux/linux_ioctl.c:2170

MFC after:	2 days

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase