mesa: do not trigger _NEW_TEXTURE_STATE in glActiveTexture()

This looks like useless because gl_context::Texture::CurrentUnit
is not used by _mesa_update_texture_state() and friends.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Brian Paul <brianp@vmware.com>

src/mesa/main/texstate.c

@@ -307,8 +307,6 @@ active_texture(GLenum texture, bool no_error)
       }
    }
 
-   FLUSH_VERTICES(ctx, _NEW_TEXTURE_STATE);
-
    ctx->Texture.CurrentUnit = texUnit;
    if (ctx->Transform.MatrixMode == GL_TEXTURE) {
       /* update current stack pointer */