There are cases where services need to remount (or change their
credentials files) when keys have expired, but it can be helpful
to have a dynamic trace point to make it easier to notify the
service to refresh the storage account key.

Here is sample output, one from mount with bad password, one
from a reconnect where the password has been changed or expired
and reconnect fails (requiring remount with new storage account key)

       TASK-PID     CPU#  |||||  TIMESTAMP  FUNCTION
          | |         |   |||||     |         |

  mount.cifs-11362  [000] .....  6000.241620: smb3_key_expired:
    rc=-13 user=testpassu conn_id=0x2 server=localhost addr=127.0.0.1:445
  kworker/4:0-8458  [004] .....  6044.892283: smb3_key_expired:
    rc=-13 user=testpassu conn_id=0x3 server=localhost addr=127.0.0.1:445
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>