Staging: hv: channel: export vmbus_teardown_gpadl to modules

Drivers need to call this directly, so export it, like other vmbus
functions.

Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Hank Janssen <hjanssen@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/hv/channel.c

@@ -637,6 +637,7 @@ int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
 	kfree(info);
 	return ret;
 }
+EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
 
 /*
  * vmbus_close - Close the specified channel