includes: Install libvirt-common.h

The libvirt-common.h is build time generated file from .in.
Obviously, it's generated into builddir and not srcdir. Problem
is, the list of header files to install, virinc_HEADERS contains
only $(srcdir)/*.h and this misses libvirt-common.h. This problem
is pretty obvious when doing a VPATH build.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

include/Makefile.am

@@ -20,6 +20,7 @@ virincdir = $(includedir)/libvirt
 
 allheaders = $(wildcard $(srcdir)/libvirt/*.h)
 virinc_HEADERS = $(filter-out $(srcdir)/libvirt/libvirt-admin.h, $(allheaders))
+virinc_HEADERS += libvirt/libvirt-common.h
 
 EXTRA_DIST = libvirt/libvirt-common.h.in