mm, oom: keep oom_adj under or at upper limit when printing

For oom_score_adj values in the range [942,999], the current
calculations will print 16 for oom_adj.  This patch simply limits the
output so output is inline with docs.

Signed-off-by: Charles Haithcock <chaithco@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Link: https://lkml.kernel.org/r/20201020165130.33927-1-chaithco@redhat.com


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>