drm/edid: use true and false for boolean values

Assign true or false to boolean variables instead of an integer value.

This issue was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180130100528.GA7154@training

drivers/gpu/drm/drm_edid.c

@@ -2767,7 +2767,7 @@ do_detailed_mode(struct detailed_timing *timing, void *c)
 
 		drm_mode_probed_add(closure->connector, newmode);
 		closure->modes++;
-		closure->preferred = 0;
+		closure->preferred = false;
 	}
 }
 
@@ -2784,7 +2784,7 @@ add_detailed_modes(struct drm_connector *connector, struct edid *edid,
 	struct detailed_mode_closure closure = {
 		.connector = connector,
 		.edid = edid,
-		.preferred = 1,
+		.preferred = true,
 		.quirks = quirks,
 	};