Change repaint_needed to bool

It is only used as a binary value.

Signed-off-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
diff --git a/libweston/compositor-fbdev.c b/libweston/compositor-fbdev.c
index 44f0cf5..6f976d1 100644
--- a/libweston/compositor-fbdev.c
+++ b/libweston/compositor-fbdev.c
@@ -693,7 +693,7 @@
 
 		wl_list_for_each(output,
 				 &compositor->output_list, link) {
-			output->repaint_needed = 0;
+			output->repaint_needed = false;
 		}
 	}
 }