Disable stateful OpenNebula driver if libvirtd is disabled

Also move the equivalent checks for LXC and UML before their header
checks. This way configure doesn't check for the headers when the driver
gets disabled anyway.

configure.ac

@@ -485,6 +485,9 @@ AC_CHECK_HEADERS([linux/kvm.h])
 dnl
 dnl check for sufficient headers for LXC
 dnl
+if test "$with_libvirtd" = "no" ; then
+  with_lxc=no
+fi
 if test "$with_lxc" = "yes" || test "$with_lxc" = "check"; then
     AC_CHECK_HEADER([sched.h],
     dnl Header is there, check for unshare()
@@ -515,9 +518,6 @@ if test "$with_lxc" = "yes" || test "$with_lxc" = "check"; then
 
     ])
 fi
-if test "$with_libvirtd" = "no" ; then
-  with_lxc=no
-fi
 if test "$with_lxc" = "yes" ; then
     AC_DEFINE_UNQUOTED([WITH_LXC], 1, [whether LXC driver is enabled])
 fi
@@ -539,6 +539,9 @@ PKG_PROG_PKG_CONFIG
 dnl OpenNebula driver Compilation setting
 dnl
 
+if test "$with_libvirtd" = "no" ; then
+  with_one=no
+fi
 XMLRPC_CFLAGS=
 XMLRPC_LIBS=
 if test "x$with_one" = "xyes" || test "x$with_one" = "xcheck"; then
@@ -1072,6 +1075,9 @@ dnl
 dnl Checks for the UML driver
 dnl
 
+if test "$with_libvirtd" = "no" ; then
+  with_uml=no
+fi
 if test "$with_uml" = "yes" || test "$with_uml" = "check"; then
     AC_CHECK_HEADER([sys/inotify.h], [
         with_uml=yes
@@ -1084,9 +1090,6 @@ if test "$with_uml" = "yes" || test "$with_uml" = "check"; then
         fi
     ])
 fi
-if test "$with_libvirtd" = "no" ; then
-  with_uml=no
-fi
 if test "$with_uml" = "yes" ; then
     AC_DEFINE_UNQUOTED([WITH_UML], 1, [whether UML driver is enabled])
 fi