i915g: Log program compile errors to mesa_loge().

i915g: Log program compile errors to mesa_loge().

Now these major driver failures are no longer hidden under -DDEBUG, and
would also work on android (you know, if you cared).  We do want to
suppress logging for u_blitter shaders that fail to compile during
util_blitter_cache_all_shaders().

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11617>