zink: remove workaround of FB modifiers forcing present state

Remove a legacy workaround where presence of modifiers in framebuffer
state results in `needs_present` to be set without a good reason.

This prevents hitting an assertion for framebuffers that use DRM
modifiers, e.g. via GBM BO alloc -> EGLImage import -> GL FBO bind.

Co-authored-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Heinrich Fink <hfink@snap.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/29715>
1 file changed