Do not check the texture's filtering mode in Texture*::updateTexture, instead check the texture's dirty flags.

With sampler objects, it becomes difficult to rely on the texture filtering mode state to determine if mipmapping
is going to be enabled in the texture, as sampler object may or may not override the texture internal state.

TRAC #23453

Signed-off-by: Nicolas Capens
Signed-off-by: Shannon Woods
Authored-by: Jamie Madill