mptcp: pm: reduce indentation blocks

commit c95eb32ced823a00be62202b43966b07b2f20b7f upstream.

That will simplify the following commits.

No functional changes intended.

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20240731-upstream-net-20240731-mptcp-endp-subflow-signal-v1-3-c8a9b036493b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: cd7c957f936f ("mptcp: pm: don't try to create sf if alloc failed")
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>