coredump: don't pointlessly check and spew warnings

When a write happens it doesn't make sense to check perform checks on
the input. Skip them.

Whether a fixes tag is licensed is a bit of a gray area here but I'll
add one for the socket validation part I added recently.

Link: https://lore.kernel.org/20250821-moosbedeckt-denunziant-7908663f3563@brauner


Fixes: 16195d2c ("coredump: validate socket name as it is written")
Reported-by: Brad Spengler <brad.spengler@opensrcsec.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>