perf tools: Fix bug in isupper() and islower()

One of the reasons 'perf test' is failing on Power appears to be due to
a bug in isupper().

isupper(c) and islower(c) should be checking 'c' against the mask 0x20.
Instead they are checking sane_ctype[c] which causes isupper() to be
true for lower case letters.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/20130329192950.GA9312@us.ibm.com


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