ifmcstat fails to build without KVM and with INET6

Hello all,

I'm having difficulty compiling a freshly updated checkout of head  
using WITHOUT_KVM src.conf.  The error is in src/usr.sbin/ifmcstat/ 
ifmcstat.c.  It appears the problem is due to the in6_ifinfo()  
function definition being incorrectly under an #ifdef WITH_KVM  
section.  I was able to fix the problem with the attached patch.

Just FYI in case anyone else hits this problem.

- Ben