We recently added some new locking to this function but one error path
was overlooked. We need to drop the lock before returning.
Fixes: f4da56529d ("net: stmmac: Add support for external trigger timestamping")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Wong Vee Khee <vee.khee.wong@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>