drm/i915: Fix wrong initializer for "locked" variable in assert_panel_unlocked

Otherwise it just contains random memory.

Issue detected by cppcheck.
Signed-off-by: NThomas Jarosch <thomas.jarosch@intra2net.com>
Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NKeith Packard <keithp@keithp.com>

drivers/gpu/drm/i915/intel_display.c

@@ -878,7 +878,7 @@ static void assert_panel_unlocked(struct drm_i915_private *dev_priv,
 	int pp_reg, lvds_reg;
 	u32 val;
 	enum pipe panel_pipe = PIPE_A;
-	bool locked = locked;
+	bool locked = true;
 
 	if (HAS_PCH_SPLIT(dev_priv->dev)) {
 		pp_reg = PCH_PP_CONTROL;