devlink: Fix length of eswitch inline-mode

Set eswitch inline-mode to be u8, not u16. Otherwise, errors below

$ devlink dev eswitch set pci/0000:08:00.0 mode switchdev \
  inline-mode network
    Error: Attribute failed policy validation.
    kernel answers: Numerical result out of rang
    netlink: 'devlink': attribute type 26 has an invalid length.

Fixes: f2f9dd1 ("netlink: specs: devlink: add the remaining command to generate complete split_ops")
Signed-off-by: William Tu <witu@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240310164547.35219-1-witu@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: williamtu

Documentation/netlink/specs/devlink.yaml

@@ -290,7 +290,7 @@ attribute-sets:
         enum: eswitch-mode
       -
         name: eswitch-inline-mode
-        type: u16
+        type: u8
         enum: eswitch-inline-mode
       -
         name: dpipe-tables

net/devlink/netlink_gen.c

@@ -198,7 +198,7 @@ static const struct nla_policy devlink_eswitch_set_nl_policy[DEVLINK_ATTR_ESWITC
 	[DEVLINK_ATTR_BUS_NAME] = { .type = NLA_NUL_STRING, },
 	[DEVLINK_ATTR_DEV_NAME] = { .type = NLA_NUL_STRING, },
 	[DEVLINK_ATTR_ESWITCH_MODE] = NLA_POLICY_MAX(NLA_U16, 1),
-	[DEVLINK_ATTR_ESWITCH_INLINE_MODE] = NLA_POLICY_MAX(NLA_U16, 3),
+	[DEVLINK_ATTR_ESWITCH_INLINE_MODE] = NLA_POLICY_MAX(NLA_U8, 3),
 	[DEVLINK_ATTR_ESWITCH_ENCAP_MODE] = NLA_POLICY_MAX(NLA_U8, 1),
 };