compositor-wayland: Convert use-pixman flag to boolean

Signed-off-by: Armin Krezović <krezovic.armin@gmail.com>
Reviewed-by: Quentin Glidic <sardemff7+git@sardemff7.net>
diff --git a/libweston/compositor-wayland.h b/libweston/compositor-wayland.h
index 58e0fb1..9a9dde8 100644
--- a/libweston/compositor-wayland.h
+++ b/libweston/compositor-wayland.h
@@ -38,7 +38,7 @@
 
 struct weston_wayland_backend_config {
 	struct weston_backend_config base;
-	int use_pixman;
+	bool use_pixman;
 	int sprawl;
 	char *display_name;
 	int fullscreen;