perf symbols: Correct comment wrt kallsyms loading

In kallsyms_parse() when calling process_symbol() (a callback argument
to kallsyms_parse()), we pass start as both start & end (ie:
start=start, end=start).

In map__process_kallsym_symbol(), the length is calculated as 'end -
start + 1', making the length 1, not 0.

Essentially, start & end define an inclusive range.

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: David Hansen <dave@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Matt Hellsley <matthltc@us.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1344637382-22789-2-git-send-email-cody@linux.vnet.ibm.com


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