configure: fix enable_simple_intel_dmabuf_client=auto

When the user does not specify --enable nor
--disable-simple-intel-dmabuf-client, we want to autodetect based on
dependencies. cb512c018e implemented this,
but forgot to actually enable it if the autodetect comes positive.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Daniel Stone <daniels@collabora.com>

configure.ac

@@ -348,6 +348,7 @@ if ! test "x$enable_simple_intel_dmabuf_client" = "xno"; then
   if test "x$have_simple_dmabuf_client" = "xno" -a "x$enable_simple_intel_dmabuf_client" = "xyes"; then
     AC_MSG_ERROR([Intel dmabuf client explicitly enabled, but libdrm_intel couldn't be found])
   fi
+  enable_simple_intel_dmabuf_client="$have_simple_dmabuf_client"
 fi
 AM_CONDITIONAL(BUILD_SIMPLE_INTEL_DMABUF_CLIENT, test "x$enable_simple_intel_dmabuf_client" = "xyes")