Revert "xf86drmMode: set FB_MODIFIERS flag when modifiers are supplied"

This reverts commit b362850689d1b0048b7f4641cc236128b5a43773.

This breaks when the kernel driver does not support modifiers and the
application properly zeroes the modifiers.

Acked-by: Simon Ser <contact@emersion.fr>
diff --git a/xf86drmMode.c b/xf86drmMode.c
index dc17724..c3920b9 100644
--- a/xf86drmMode.c
+++ b/xf86drmMode.c
@@ -289,10 +289,8 @@
 	memcpy(f.handles, bo_handles, 4 * sizeof(bo_handles[0]));
 	memcpy(f.pitches, pitches, 4 * sizeof(pitches[0]));
 	memcpy(f.offsets, offsets, 4 * sizeof(offsets[0]));
-	if (modifier) {
-		f.flags |= DRM_MODE_FB_MODIFIERS;
+	if (modifier)
 		memcpy(f.modifier, modifier, 4 * sizeof(modifier[0]));
-	}
 
 	if ((ret = DRM_IOCTL(fd, DRM_IOCTL_MODE_ADDFB2, &f)))
 		return ret;