drm: Replace kzalloc with kcalloc

Prefer kcalloc over kzalloc to allocate an array.
This patch fixes checkcpatch issue.

Signed-off-by: Harsha Sharma <harshasharmaiitr@gmail.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20171013073747.29877-1-harshasharmaiitr@gmail.com
Link: https://patchwork.freedesktop.org/patch/msgid/20171013073747.29877-1-harshasharmaiitr@gmail.com

drivers/gpu/drm/drm_crtc_helper.c

@@ -562,12 +562,12 @@ int drm_crtc_helper_set_config(struct drm_mode_set *set,
 	 * Allocate space for the backup of all (non-pointer) encoder and
 	 * connector data.
 	 */
-	save_encoder_crtcs = kzalloc(dev->mode_config.num_encoder *
+	save_encoder_crtcs = kcalloc(dev->mode_config.num_encoder,
 				sizeof(struct drm_crtc *), GFP_KERNEL);
 	if (!save_encoder_crtcs)
 		return -ENOMEM;
 
-	save_connector_encoders = kzalloc(dev->mode_config.num_connector *
+	save_connector_encoders = kcalloc(dev->mode_config.num_connector,
 				sizeof(struct drm_encoder *), GFP_KERNEL);
 	if (!save_connector_encoders) {
 		kfree(save_encoder_crtcs);

drivers/gpu/drm/drm_fb_helper.c

@@ -2266,7 +2266,7 @@ static int drm_pick_crtcs(struct drm_fb_helper *fb_helper,
 	if (modes[n] == NULL)
 		return best_score;
 
-	crtcs = kzalloc(fb_helper->connector_count *
+	crtcs = kcalloc(fb_helper->connector_count,
 			sizeof(struct drm_fb_helper_crtc *), GFP_KERNEL);
 	if (!crtcs)
 		return best_score;

drivers/gpu/drm/drm_plane_helper.c

@@ -354,7 +354,7 @@ int drm_primary_helper_update(struct drm_plane *plane, struct drm_crtc *crtc,
 	/* Find current connectors for CRTC */
 	num_connectors = get_connectors_for_crtc(crtc, NULL, 0);
 	BUG_ON(num_connectors == 0);
-	connector_list = kzalloc(num_connectors * sizeof(*connector_list),
+	connector_list = kcalloc(num_connectors, sizeof(*connector_list),
 				 GFP_KERNEL);
 	if (!connector_list)
 		return -ENOMEM;