svc: Make svc_send transport neutral

Move the sk_mutex field to the transport independent svc_xprt structure.
Now all the fields that svc_send touches are transport neutral. Change the
svc_send function to use the transport independent svc_xprt directly instead
of the transport dependent svc_sock structure.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Acked-by: Neil Brown <neilb@suse.de>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Greg Banks <gnb@sgi.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

include/linux/sunrpc/svc_xprt.h

@@ -54,6 +54,7 @@ struct svc_xprt {
 	struct svc_pool		*xpt_pool;	/* current pool iff queued */
 	struct svc_serv		*xpt_server;	/* service for transport */
 	atomic_t    	    	xpt_reserved;	/* space on outq that is rsvd */
+	struct mutex		xpt_mutex;	/* to serialize sending data */
 };
 
 int	svc_reg_xprt_class(struct svc_xprt_class *);

include/linux/sunrpc/svcsock.h

@@ -24,7 +24,6 @@ struct svc_sock {
 						 * sk_info_authunix */
 	struct list_head	sk_deferred;	/* deferred requests that need to
 						 * be revisted */
-	struct mutex		sk_mutex;	/* to serialize sending data */
 
 	/* We keep the old state_change and data_ready CB's here */
 	void			(*sk_ostate)(struct sock *);