mei: use type struct mei_cl *cl instead of void in struct mei_cb

We can use correct type 'struct mei_cl' instead of
'void *' for file_private in the struct mei_cb
as there is no other type assigned to this member of the structure

We rename the member from file_private to cl

Remove about 10 lines of declarations of temporary variables
used for type casting

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mei/mei_dev.h

@@ -143,10 +143,17 @@ struct mei_message_data {
 };
 
 
+struct mei_cl;
+
+/*
+ * struct mei_cl_cb - file operation callback structure
+ *
+ * @cl - file client who is running this operation
+ */
 struct mei_cl_cb {
 	struct list_head list;
+	struct mei_cl *cl;
 	enum mei_cb_major_types major_file_operations;
-	void *file_private;
 	struct mei_message_data request_buffer;
 	struct mei_message_data response_buffer;
 	unsigned long buf_idx;