cgroup/dmem: Fix parameters documentation

cgroup/dmem: Fix parameters documentation

During the dmem cgroup development, the parameters to the
dmem_cgroup_state_evict_valuable() and dmem_cgroup_try_charge() were
changed, but the documentation wasn't adjusted accordingly.

This results in a documentation build warning. Adjust the documentation
to reflect what the final functions parameters are.

Fixes: b168ed458dde ("kernel/cgroup: Add "dmem" memory accounting cgroup")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/r/20250113160334.1f09f881@canb.auug.org.au/
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Simona Vetter <simona.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20250113092608.1349287-2-mripard@kernel.org
Signed-off-by: Maxime Ripard <mripard@kernel.org>