drm/sti: clarify the skip frame/field message

When a frame or a field is skipped, output a Warning message instead of
an Error message.
Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
Reviewed-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Reviewed-by: Vincent Abriou <vincent.abriou@st.com>

drivers/gpu/drm/sti/sti_hqvdp.c

@@ -580,7 +580,7 @@ int sti_hqvdp_vtg_cb(struct notifier_block *nb, unsigned long evt, void *data)
 		btm_cmd_offset = sti_hqvdp_get_free_cmd(hqvdp);
 		top_cmd_offest = sti_hqvdp_get_curr_cmd(hqvdp);
 		if ((btm_cmd_offset == -1) || (top_cmd_offest == -1)) {
-			DRM_ERROR("Cannot get cmds, skip btm field\n");
+			DRM_DEBUG_DRIVER("Warning: no cmd, will skip field\n");
 			return -EBUSY;
 		}
 
@@ -810,7 +810,7 @@ static void sti_hqvdp_atomic_update(struct drm_plane *drm_plane,
 
 	cmd_offset = sti_hqvdp_get_free_cmd(hqvdp);
 	if (cmd_offset == -1) {
-		DRM_ERROR("No available hqvdp_cmd now\n");
+		DRM_DEBUG_DRIVER("Warning: no cmd, will skip frame\n");
 		return;
 	}
 	cmd = hqvdp->hqvdp_cmd + cmd_offset;