selftests/mm: drop unnecessary sudo usage

This script must be run as root anyway (see all the writing to privileged
files in /proc etc).

Remove the unnecessary use of sudo to avoid breaking on single-user
systems that don't have sudo.  This also avoids confusing readers.

Link: https://lkml.kernel.org/r/20250311-mm-selftests-v4-9-dec210a658f5@google.com


Signed-off-by: Brendan Jackman <jackmanb@google.com>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>