build: qemu-ga: fix VSS dependencies

Currently VSS dll/tlb files for use in w32 builds are only built as a
result of having been added to the general 'tools' target alongside
qemu-ga. This is fine for default make target, but if we build
qemu-ga directly via `make qemu-ga.exe`, the VSS files are not
created.

Fix this by moving the VSS dependencies to qemu-ga.exe directly.
With this move we can move the VSS files back out of 'tools',
and drop the extra handling from MSI target in Makefile.

Now we can build qemu-ga MSI package with:
  ./configure ...
  make qemu-ga.exe
  make msi

or simply:
  ./configure ...
  make msi

and no longer need to do a full build beforehand.

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
diff --git a/configure b/configure
index a52ef50..21c4089 100755
--- a/configure
+++ b/configure
@@ -3851,6 +3851,7 @@
     guest_agent_with_vss="yes"
     QEMU_CFLAGS="$QEMU_CFLAGS $vss_win32_include"
     libs_qga="-lole32 -loleaut32 -lshlwapi -luuid -lstdc++ -Wl,--enable-stdcall-fixup $libs_qga"
+    qga_vss_provider="qga/vss-win32/qga-vss.dll qga/vss-win32/qga-vss.tlb"
   else
     if test "$vss_win32_sdk" != "" ; then
       echo "ERROR: Please download and install Microsoft VSS SDK:"
@@ -4350,9 +4351,6 @@
 if [ "$guest_agent" != "no" ]; then
   if [ "$linux" = "yes" -o "$bsd" = "yes" -o "$solaris" = "yes" -o "$mingw32" = "yes" ] ; then
       tools="qemu-ga\$(EXESUF) $tools"
-      if [ "$mingw32" = "yes" -a "$guest_agent_with_vss" = "yes" ]; then
-        tools="qga/vss-win32/qga-vss.dll qga/vss-win32/qga-vss.tlb $tools"
-      fi
       guest_agent=yes
   elif [ "$guest_agent" != yes ]; then
       guest_agent=no
@@ -4660,6 +4658,7 @@
   echo "CONFIG_PRODUCTVERSION=$version_major,$version_minor,$version_subminor,$version_micro" >> $config_host_mak
   if test "$guest_agent_with_vss" = "yes" ; then
     echo "CONFIG_QGA_VSS=y" >> $config_host_mak
+    echo "QGA_VSS_PROVIDER=$qga_vss_provider" >> $config_host_mak
     echo "WIN_SDK=\"$win_sdk\"" >> $config_host_mak
   fi
   if test "$guest_agent_ntddscsi" = "yes" ; then