staging: ccree: use sizeof(*var) in kmalloc

Fix the following checkpatch warning:

CHECK: Prefer kmalloc(sizeof(*buff_mgr_handle)...)
over kmalloc(sizeof(struct buff_mgr_handle)...)
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Acked-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/ccree/ssi_buffer_mgr.c

@@ -1725,7 +1725,7 @@ int ssi_buffer_mgr_init(struct ssi_drvdata *drvdata)
 	struct buff_mgr_handle *buff_mgr_handle;
 	struct device *dev = &drvdata->plat_dev->dev;
 
-	buff_mgr_handle = kmalloc(sizeof(struct buff_mgr_handle), GFP_KERNEL);
+	buff_mgr_handle = kmalloc(sizeof(*buff_mgr_handle), GFP_KERNEL);
 	if (!buff_mgr_handle)
 		return -ENOMEM;