Use ErrorF for an error message after an xcalloc failure, and return instead of falling through to GlxSetVisualConfigs, or abort()ing at the test branch.
(cherry picked from commit 1056700971fd5c034396ed6dbea15e092f0c6332)
Add a setVisualConfigs that is called before the fbScreenInit, to setup the __GLXvisualConfigs.
(cherry picked from commit fc86f9e4482043eca76d9d7a96e166be1aabf674)