hvsupport: Adapt to vbox driver rewrite

Since vbox driver rewrite the virDriver structure init moved from
vbox_tmpl.c into vbox_common.c. However, our hvsupport.pl script
doesn't count with that. It still parses vbox_tmp.c and looks for
virDriver structure which is not found there anymore. As a result,
at hvsupport page is seems like vbox driver doesn't support
anything.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>

docs/hvsupport.pl

@@ -28,7 +28,7 @@ my %groupheaders = (
 my @srcs;
 find({
     wanted => sub {
-        if (m!$srcdir/.*/\w+_(driver|tmpl|monitor|hal|udev)\.c$!) {
+        if (m!$srcdir/.*/\w+_(driver|common|tmpl|monitor|hal|udev)\.c$!) {
             push @srcs, $_ if $_ !~ /vbox_driver\.c/;
         }
     }, no_chdir => 1}, $srcdir);