mm/secretmem: remove redundant initiialization of pointer file

mm/secretmem: remove redundant initiialization of pointer file

The pointer file is being initialized with a value that is never read, it
is being re-assigned later on.  Clean up code by removing the redundant
initialization.

Link: https://lkml.kernel.org/r/20230116164332.79500-1-colin.i.king@gmail.com
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foudation.org>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>