sysctl: remove struct ctl_path

All usages of this struct have been removed from the kernel tree.

The struct is still referenced by scripts/check-sysctl-docs but that
script is broken anyways as it only supports the register_sysctl_paths()
API and not the currently used register_sysctl() one.

Fixes: 0199849 ("sysctl: remove register_sysctl_paths()")
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

Author: t-8ch

include/linux/sysctl.h

@@ -210,11 +210,6 @@ struct ctl_table_root {
 	int (*permissions)(struct ctl_table_header *head, struct ctl_table *table);
 };
 
-/* struct ctl_path describes where in the hierarchy a table is added */
-struct ctl_path {
-	const char *procname;
-};
-
 #define register_sysctl(path, table)	\
 	register_sysctl_sz(path, table, ARRAY_SIZE(table))