sfc: initialize dynamic sysfs attributes for lockdep

Dynamically allocated sysfs attributes must be initialized using
sysfs_attr_init(), otherwise lockdep complains:
BUG: key <address> not in .data!
Signed-off-by: NMichal Schmidt <mschmidt@redhat.com>
Acked-by: NBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/sfc/mcdi_mon.c

@@ -222,6 +222,7 @@ efx_mcdi_mon_add_attr(struct efx_nic *efx, const char *name,
 	attr->index = index;
 	attr->type = type;
 	attr->limit_value = limit_value;
+	sysfs_attr_init(&attr->dev_attr.attr);
 	attr->dev_attr.attr.name = attr->name;
 	attr->dev_attr.attr.mode = S_IRUGO;
 	attr->dev_attr.show = reader;