gphoto2.ds: Make use of `gphoto2-config --libs` for the configure check.

configure

@@ -13488,7 +13488,7 @@ if test "${ac_cv_lib_gphoto2_gp_camera_new+set}" = set; then
   echo $ECHO_N "(cached) $ECHO_C" >&6
 else
   ac_check_lib_save_LIBS=$LIBS
-LIBS="-lgphoto2 $GPHOTO2LIBS $LIBS"
+LIBS="-lgphoto2 $ac_gphoto2_libs $LIBS"
 cat >conftest.$ac_ext <<_ACEOF
 /* confdefs.h.  */
 _ACEOF

configure.ac

@@ -951,7 +951,7 @@ then
                                   [AC_DEFINE(HAVE_GPHOTO2, 1, [Define if we have libgphoto2 development environment])
                                    AC_SUBST(GPHOTO2LIBS,"$ac_gphoto2_libs")
                                    AC_SUBST(GPHOTO2INCL,"$ac_gphoto2_incl")],,
-                                  [$GPHOTO2LIBS])])
+                                  [$ac_gphoto2_libs])])
     CPPFLAGS="$ac_save_CPPFLAGS"
 fi
 WINE_NOTICE_WITH(gphoto,[test "$ac_cv_lib_gphoto2_gp_camera_new" != "yes"],