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
diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c
index eab36a4..5a84c3b 100644
--- a/drivers/gpu/drm/drm_crtc_helper.c
+++ b/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);