[PATCH] nvme-fabrics: error out to unlock the mutex

[Sagi Grimberg]

> Currently, in the nvmf_host_add() function, if the nvmf_host_alloc()
> call failed to allocate memory for the host, the code would directly
> return -ENOMEM without unlocking the nvmf_hosts_mutex. This could
> lead to potential issues with mutex synchronization.
> 
> Fix that error handling mechanism by jumping to the out_unlock label
> when nvmf_host_alloc() fails. This ensures that the mutex is unlocked
> before returning the error code. The updated code enhances avoids
> possible deadlocks.
> 
> Reported-by: kernel test robot <lkp at intel.com>
> Reported-by: Julia Lawall <julia.lawall at inria.fr>
> Closes: https://lore.kernel.org/r/202306020909.MTUEBeIa-lkp@intel.com/
> Signed-off-by: Chaitanya Kulkarni <kch at nvidia.com>

Can add:
Fixes: f0cebf82004d ("nvme-fabrics: prevent overriding of existing host")

otherwise:
Reviewed-by: Sagi Grimberg <sagi at grimberg.me>