Merge branch 'ipv6-fix-error-handling-in-disable_ipv6-sysctl'

Fernando Fernandez Mancera says:

====================
ipv6: fix error handling in disable_ipv6 sysctl

While working on a different IPv6 patch series I have spotted multiple
minor bugs around sysctl error handling and notifications. In general,
they are not serious issues.

In addition, there is one more issue in forwarding sysctl as it does not
check for CAP_NET_ADMIN for the namespace. I am keeping that patch out
of this series and I am aiming it at the net-next tree once it re-opens.

During v3, Ido's pointed out that it is unnecessary to reset the
position pointer when the return value is negative as at
new_sync_write() the ppos is only advanced when ret return value is
positive. That means we can get rid of that operation in ipv4/ipv6
sysctls. That is going to be sent to net-next too.
====================

Link: https://patch.msgid.link/20260622130857.5115-1-fmancera@suse.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>