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().

Reviewed by:	glebius
MFC after:	3 days
Fix build host pollution by avoiding calling 'uname -srp' to
determine values for 'VERSION'.

Looked at by:	cperciva