mptcp: pm: kernel: add '_pm' to mptcp_nl_set_flags

Currently, in-kernel PM specific helpers are prefixed with
'mptcp_pm_nl_'. Here, '_pm' was missing from 'mptcp_nl_set_flags'.

Add '_pm' to be similar to others, and add '_all' to avoid confusions
witih the global 'mptcp_pm_nl_set_flags'.

No behavioural changes intended.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250307-net-next-mptcp-pm-reorg-v1-8-abef20ada03b@kernel.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>