perf record: Improve documentation of event parameters

- Some editing (params -> parameters)
- Point to the now more complete list of parameters in the perf list
manpage.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/1476381433-22959-1-git-send-email-andi@firstfloor.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>