libxl: remove configure check for libxl_domain_config_from_json

The libxl_domain_config_from_json API appeared in Xen 4.5, hence
there is no need to check for its existence after changing the
minimum supported Xen version to 4.6. Remove the check and its
use in the tests.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

m4/virt-driver-libxl.m4

@@ -56,13 +56,6 @@ AC_DEFUN([LIBVIRT_DRIVER_CHECK_LIBXL], [
     ],[
       LIBXL_LIBS="$LIBXL_LIBS -lxenstore -lxenctrl"
     ])
-
-    dnl Check if libxl_domain_config_from_json is available for domXML to
-    dnl libxl_domain_config tests
-    LIBS="$LIBS -lxenlight -lxenctrl"
-    AC_CHECK_FUNCS([libxl_domain_config_from_json])
-    CFLAGS="$old_CFLAGS"
-    LIBS="$old_LIBS"
   fi
 
   AC_SUBST([LIBXL_CFLAGS])

tests/libxlxml2domconfigtest.c

@@ -33,7 +33,7 @@
 
 #include "testutils.h"
 
-#if defined(WITH_LIBXL) && defined(WITH_YAJL) && defined(HAVE_LIBXL_DOMAIN_CONFIG_FROM_JSON)
+#if defined(WITH_LIBXL) && defined(WITH_YAJL)
 
 # include "internal.h"
 # include "viralloc.h"
@@ -228,4 +228,4 @@ int main(void)
     return EXIT_AM_SKIP;
 }
 
-#endif /* WITH_LIBXL && WITH_YAJL && HAVE_LIBXL_DOMAIN_CONFIG_FROM_JSON */
+#endif /* WITH_LIBXL && WITH_YAJL */