Fix --logY paramter (ignored due to typo) of graph-mmtests.sh

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Mel Gorman <mgorman@suse.de>
stress-highalloc: plot allocation latencies in point graphs

Note that due to a problem in systemtap, many allocation latencies are not
recorded in phases 1 and 2. This is because _stp_printf() doesn't expect
uses per-cpu buffers and doesn't expect the process to be rescheduled to
another CPU.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Mel Gorman <mgorman@suse.de>