Drivers: hv: vmbus: Fix memory leak in vmbus_add_channel_kobj

kobject_init_and_add() takes reference even when it fails.
According to the doc of kobject_init_and_add()：

   If this function returns an error, kobject_put() must be called to
   properly clean up the memory associated with the object.

Fix memory leak by calling kobject_put().

Fixes: c2e5df61

 ("vmbus: add per-channel sysfs info")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Reviewed-by: Juan Vazquez <juvazq@linux.microsoft.com>
Link: https://lore.kernel.org/r/20220203173008.43480-1-linmq006@gmail.com


Signed-off-by: Wei Liu <wei.liu@kernel.org>