perf tools: Fix fallback to cplus_demangle() when bfd_demangle() is not available

perf tools: Fix fallback to cplus_demangle() when bfd_demangle() is not available

In old binutils we can't access bfd_demangle(), use
cplus_demangle() just like oprofile.

Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Luis Claudio R. Gonçalves <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Frédéric Weisbecker <[email protected]>
LKML-Reference: <20090811192211[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>