The function cpu__max_cpu() returns the possible number of CPUs as
defined in the sysfs and can be used as an alternative for MAX_NR_CPUS
in write_cache.
MAX_CACHES is replaced by cpu__max_cpu() * MAX_CACHE_LVL.
Signed-off-by: Kyle Meyer <kyle.meyer@hpe.com> Reviewed-by: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russ Anderson <russ.anderson@hpe.com> Link: http://lore.kernel.org/lkml/20190827214352.94272-7-meyerk@stormcage.eag.rdlabs.hpecorp.net Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>