mlx4_ib: Memory leak on Dom0 with SRIOV.

mlx4_ib: Memory leak on Dom0 with SRIOV.

There are many scenarios when (using SR-IOV) the connection setup
tunneled from the VM through Dom0 fails for reasons such as the peer
silently dropping the connection requests due to its listener queue being
full or sends back a reject because there is no listener, the id_map_entry
is not freed on the Dom0 causing memory leak.

During testing we encountered a softlockup with multiple CPUs stuck
waiting for sriov->id_map_lock while id_map_ent_timeout was holding it for
a long time. Changing spin_lock(&sriov->id_map_lock) in id_map_ent_timeout
to spin_lock_irqsave resolved this hang.

Orabug: 21675211

Acked-by: Rama Nichanamatlu <rama.nichanamatlu@oracle.com>
Signed-off-by: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
Signed-off-by: Mukesh Kacker <mukesh.kacker@oracle.com>