drm/i915: Use standard form -EDEADLK check

Unify how we check for -EDEADLK vs. other errors from
crtc vs. encoder compute_config() calls.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210930104133.30854-1-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>

drivers/gpu/drm/i915/display/intel_display.c

@@ -7537,11 +7537,10 @@ encoder_retry:
 
 		ret = encoder->compute_config(encoder, pipe_config,
 					      connector_state);
+		if (ret == -EDEADLK)
+			return ret;
 		if (ret < 0) {
-			if (ret != -EDEADLK)
-				drm_dbg_kms(&i915->drm,
-					    "Encoder config failure: %d\n",
-					    ret);
+			drm_dbg_kms(&i915->drm, "Encoder config failure: %d\n", ret);
 			return ret;
 		}
 	}