drivers/gpu/drm/i915/intel_lvds.c: fix locking snafu

s/unlock/lock/

Addresses http://bugzilla.kernel.org/show_bug.cgi?id=12575

Reported-by: Daniel Vetter <daniel@ffwll.ch>
Cc: Dave Airlie <airlied@linux.ie>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Eric Anholt <eric@anholt.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/gpu/drm/i915/intel_lvds.c

@@ -311,7 +311,7 @@ static int intel_lvds_get_modes(struct drm_connector *connector)
 	if (dev_priv->panel_fixed_mode != NULL) {
 		struct drm_display_mode *mode;
 
-		mutex_unlock(&dev->mode_config.mutex);
+		mutex_lock(&dev->mode_config.mutex);
 		mode = drm_mode_duplicate(dev, dev_priv->panel_fixed_mode);
 		drm_mode_probed_add(connector, mode);
 		mutex_unlock(&dev->mode_config.mutex);