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_plane_helper.c b/drivers/gpu/drm/drm_plane_helper.c
index 06aee17..759ed93 100644
--- a/drivers/gpu/drm/drm_plane_helper.c
+++ b/drivers/gpu/drm/drm_plane_helper.c
@@ -354,7 +354,7 @@
 	/* 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;