net: sch_generic remove redundant use of <linux/module.h>

This file has modular references, but they are limited to
those which are covered by the simple "struct module;"
declaration used in dozens of other places. In fact that
declaration is already there (just outside of the context
of this commit) so simply remove the include line.

Signed-off-by: Paul Gortmaker <[e-mail]>

include/net/sch_generic.h

···
 #include <linux/netdevice.h>
 #include <linux/types.h>
 #include <linux/rcupdate.h>
-#include <linux/module.h>
 #include <linux/pkt_sched.h>
 #include <linux/pkt_cls.h>
 #include <net/gen_stats.h>