pstore/zone: Don't clear memory twice

There is no need to call memset(..., 0, ...) on memory allocated by
kcalloc(). It is already zeroed.

Remove the redundant call.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/fa2597400051c18c6ca11187b0e4b906729991b2.1709972649.git.christophe.jaillet@wanadoo.fr


Signed-off-by: Kees Cook <keescook@chromium.org>