mesa/program_interface_query: fix transform feedback varyings.

The spec says gl_NextBuffer and gl_SkipComponents need to be
returned to userspace in the program interface queries.

We currently throw those away, this requires a complete piglit
run to make sure no drivers fallover due to the extra varyings.

This fixes:
GL45-CTS.program_interface_query.transform-feedback-built-in

Reviewed-by: Timothy Arceri <timothy.arceri@collabora.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

src/mesa/main/shader_query.cpp

@@ -1143,7 +1143,7 @@ _mesa_program_resource_prop(struct gl_shader_program *shProg,
          *val = MAX2(_mesa_program_resource_array_size(res), 1);
          return 1;
       case GL_TRANSFORM_FEEDBACK_VARYING:
-         *val = MAX2(RESOURCE_XFV(res)->Size, 1);
+         *val = RESOURCE_XFV(res)->Size;
          return 1;
       default:
          goto invalid_operation;