Eliminate key press requirement "show vmopag" command output.

[stevek]

Summary

One was required to press a key to continue after every 18 lines of
output. This requirement had been in the "show vmopag" command since it
was introduced, which was many years before paging was added to DDB.
With paging, this explict key check is no longer necessary.

Obtained from: Juniper Networks, Inc.
MFC after: 1 week

Test Plan

Run "show vmopag" from db> prompt and see that it does not need additional
keypresses other than the ones needed for the pager.

[jhb]

Magic 18's and not documented at all,

sys/vm/vm_object.c

2838

Somewhere (perhaps at the end of the loop) you might want to throw in a

if (db_pager_quit)
    return;

To allow exiting the output if it is long. I'm not sure if you really want to put it in all the places that checked before, maybe just at the start of each TAILQ_FOREACH() loop (both outer and inner)?

[mhorne]

Thanks, this saves me a submission.

sys/vm/vm_object.c

2838

This is exactly where I placed these returns in my diff. The output is quite long so I would say they are necessary.

[stevek]

Add db_pager_quit checks per review comments