RDMA/srp: Fix error handling in srp_add_port

As comment of device_add() says, if device_add() succeeds, you should
call device_del() when you want to get rid of it. If device_add() has
not succeeded, use only put_device() to drop the reference count.

Add a put_device() call before returning from the function to decrement
reference count for cleanup.

Found by code review.

Fixes: c8e4c23 ("RDMA/srp: Rework the srp_add_port() error path")
Signed-off-by: Ma Ke <make_ruc2021@163.com>
Link: https://patch.msgid.link/20241217075538.2909996-1-make_ruc2021@163.com
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

Author: Ma Ke

drivers/infiniband/ulp/srp/ib_srp.c

@@ -3978,7 +3978,6 @@ static struct srp_host *srp_add_port(struct srp_device *device, u32 port)
 	return host;
 
 put_host:
-	device_del(&host->dev);
 	put_device(&host->dev);
 	return NULL;
 }