sgi-xp: Replace spin_is_locked() with lockdep

lockdep_assert_held() is better suited to checking locking requirements,
since it won't get confused when someone else holds the lock. This is
also a step towards possibly removing spin_is_locked().

Signed-off-by: Lance Roy <[e-mail]>
Cc: Cliff Whickman <[e-mail]>
Cc: Arnd Bergmann <[e-mail]>
Acked-by: Robin Holt <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/misc/sgi-xp/xpc_channel.c

···
 {
 	enum xp_retval ret;
 
-	DBUG_ON(!spin_is_locked(&ch->lock));
+	lockdep_assert_held(&ch->lock);
 
 	if (!(ch->flags & XPC_C_OPENREQUEST) ||
 	    !(ch->flags & XPC_C_ROPENREQUEST)) {
···
 	struct xpc_partition *part = &xpc_partitions[ch->partid];
 	u32 channel_was_connected = (ch->flags & XPC_C_WASCONNECTED);
 
-	DBUG_ON(!spin_is_locked(&ch->lock));
+	lockdep_assert_held(&ch->lock);
 
 	if (!(ch->flags & XPC_C_DISCONNECTING))
 		return;
···
 {
 	u32 channel_was_connected = (ch->flags & XPC_C_CONNECTED);
 
-	DBUG_ON(!spin_is_locked(&ch->lock));
+	lockdep_assert_held(&ch->lock);
 
 	if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_DISCONNECTED))
 		return;

drivers/misc/sgi-xp/xpc_sn2.c

···
 {
 	struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
 
-	DBUG_ON(!spin_is_locked(&ch->lock));
+	lockdep_assert_held(&ch->lock);
 
 	ch_sn2->remote_msgqueue_pa = 0;
 

drivers/misc/sgi-xp/xpc_uv.c

···
 {
 	struct xpc_channel_uv *ch_uv = &ch->sn.uv;
 
-	DBUG_ON(!spin_is_locked(&ch->lock));
+	lockdep_assert_held(&ch->lock);
 
 	kfree(ch_uv->cached_notify_gru_mq_desc);
 	ch_uv->cached_notify_gru_mq_desc = NULL;