If call stack capture is enabled for context switch data, the 64KB buffer is
too small to work without overruns. However, if the default buffer size is
increased, then the maximum locked memory limit is hit.
This change keeps the small buffer size for all the buffers that may be used
without escalated privileges. The context switch buffer is bigger, but it does
not need to obey the limits, as the application is running as root, if it is
to be used.
