tools/mm/page-types: fix kpageflags option argument in getopt_long

tools/mm/page-types: fix kpageflags option argument in getopt_long

The --kpageflags option requires an argument to specify the kpageflags
file path, but has_arg was set to 0 (no_argument) in the long options
table.  Change it to 1 (required_argument) so getopt_long correctly parses
the argument.

Link: https://lore.kernel.org/20260513022120.58033-4-ye.liu@linux.dev
Signed-off-by: Ye Liu <liuye@kylinos.cn>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>