drm/i915: Adjust intel_crtc_compute_config() debug message

"CRTC fixup failed" is probably leftovers from pre-atomic days
when there was an actual fixup() function. Let's unify the debug
messages between encoder vs. crtc compute_config() calls.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210930104133.30854-2-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>