drm/bridge: dw-mipi-dsi: Use kmemdup cf. kmalloc+memcpy

kmemdup can be used instead of kmalloc+memcpy. Replace an occurrence of
this pattern.

Issue identified with Coccinelle.
Signed-off-by: Alex Dewar <alex.dewar90@gmail.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200909190213.156302-1-alex.dewar90@gmail.com

drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c

@@ -1049,12 +1049,10 @@ static void debugfs_create_files(void *data)
 	};
 	int i;
 
-	dsi->debugfs_vpg = kmalloc(sizeof(debugfs), GFP_KERNEL);
+	dsi->debugfs_vpg = kmemdup(debugfs, sizeof(debugfs), GFP_KERNEL);
 	if (!dsi->debugfs_vpg)
 		return;
 
-	memcpy(dsi->debugfs_vpg, debugfs, sizeof(debugfs));
-
 	for (i = 0; i < ARRAY_SIZE(debugfs); i++)
 		debugfs_create_file(dsi->debugfs_vpg[i].name, 0644,
 				    dsi->debugfs, &dsi->debugfs_vpg[i],