i40e: Fix a bug where a client close can be called before an open is complete

i40e: Fix a bug where a client close can be called before an open is complete

Orabug: 24568124

The client->open call in this path was not protected with the
client instance mutex, and hence the client->close can get initiated
before the open completes.

Change-Id: I0ed60c38868dd3f44966b6ed49a063d0e5b7edf5
Signed-off-by: Anjali Singhai Jain <anjali.singhai@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
(cherry picked from commit 3a0f52928a0a06a7c4c735cd325ca646a1e40fae)
Signed-off-by: Brian Maly <brian.maly@oracle.com>
Signed-off-by: Dhaval Giani <dhaval.giani@oracle.com>