drivers: hv: remove redundant assignment to pointer primary_channel

The pointer primary_channel is being assigned with a value that is never
used. The assignment is redundant and can be removed.  Move the
definition of primary_channel to a narrower scope.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20200414152343.243166-1-colin.king@canonical.com
[ wei: move primary_channel and update commit message ]
Signed-off-by: Wei Liu <wei.liu@kernel.org>

drivers/hv/channel_mgmt.c

@@ -400,7 +400,6 @@ static void vmbus_release_relid(u32 relid)
 
 void hv_process_channel_removal(struct vmbus_channel *channel)
 {
-	struct vmbus_channel *primary_channel;
 	unsigned long flags;
 
 	lockdep_assert_held(&vmbus_connection.channel_mutex);
@@ -425,10 +424,8 @@ void hv_process_channel_removal(struct vmbus_channel *channel)
 
 	if (channel->primary_channel == NULL) {
 		list_del(&channel->listentry);
-
-		primary_channel = channel;
 	} else {
-		primary_channel = channel->primary_channel;
+		struct vmbus_channel *primary_channel = channel->primary_channel;
 		spin_lock_irqsave(&primary_channel->lock, flags);
 		list_del(&channel->sc_list);
 		spin_unlock_irqrestore(&primary_channel->lock, flags);