MFC r326362:
Disallow TUN and TAP character device IOCTLs to modify the network device
type to any value. This can cause page faults and panics due to accessing
uninitialized fields in the "struct ifnet" which are specific to the network
device type.

Found by: jau@iki.fi
PR: 223767
Sponsored by: Mellanox Technologies

MFC r257078
Fix panic in the tap driver when a tap and vmnet interface were
created after each other e.g.

ifconfig tap0
ifconfig vmnet0
<panic>

Appears to be a cut'n'paste error from the tap code to the vmnet
code where the name string wasn't updated in the call to make_dev().

Approved by: re (glebius)

MFC r257078
Fix panic in the tap driver when a tap and vmnet interface were
created after each other e.g.

ifconfig tap0
ifconfig vmnet0
<panic>

Appears to be a cut'n'paste error from the tap code to the vmnet
code where the name string wasn't updated in the call to make_dev().

Approved by: re (glebius)