net: dsa: rename switch operations structure

Now that the dsa_switch_driver structure contains only function pointers
as it is supposed to, rename it to the more appropriate dsa_switch_ops,
uniformly to any other operations structure in the kernel.

No functional changes here, basically just the result of something like:
s/dsa_switch_driver *drv/dsa_switch_ops *ops/g

However keep the {un,}register_switch_driver functions and their
dsa_switch_drivers list as is, since they represent the -- likely to be
deprecated soon -- legacy DSA registration framework.

In the meantime, also fix the following checks from checkpatch.pl to
make it happy with this patch:

    CHECK: Comparison to NULL could be written "!ops"
    #403: FILE: net/dsa/dsa.c:470:
    +	if (ops == NULL) {

    CHECK: Comparison to NULL could be written "ds->ops->get_strings"
    #773: FILE: net/dsa/slave.c:697:
    +		if (ds->ops->get_strings != NULL)

    CHECK: Comparison to NULL could be written "ds->ops->get_ethtool_stats"
    #824: FILE: net/dsa/slave.c:785:
    +	if (ds->ops->get_ethtool_stats != NULL)

    CHECK: Comparison to NULL could be written "ds->ops->get_sset_count"
    #835: FILE: net/dsa/slave.c:798:
    +		if (ds->ops->get_sset_count != NULL)

    total: 0 errors, 0 warnings, 4 checks, 784 lines checked

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/dsa.h b/include/net/dsa.h
index 8ca2684..2ebeba4 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -165,9 +165,9 @@
 	struct dsa_chip_data	*cd;
 
 	/*
-	 * The used switch driver.
+	 * The switch operations.
 	 */
-	struct dsa_switch_driver	*drv;
+	struct dsa_switch_ops	*ops;
 
 	/*
 	 * An array of which element [a] indicates which port on this
@@ -236,7 +236,7 @@
 struct switchdev_obj_port_fdb;
 struct switchdev_obj_port_vlan;
 
-struct dsa_switch_driver {
+struct dsa_switch_ops {
 	struct list_head	list;
 
 	/*
@@ -371,8 +371,8 @@
 				 int (*cb)(struct switchdev_obj *obj));
 };
 
-void register_switch_driver(struct dsa_switch_driver *type);
-void unregister_switch_driver(struct dsa_switch_driver *type);
+void register_switch_driver(struct dsa_switch_ops *type);
+void unregister_switch_driver(struct dsa_switch_ops *type);
 struct mii_bus *dsa_host_dev_to_mii_bus(struct device *dev);
 
 static inline void *ds_to_priv(struct dsa_switch *ds)