perf tools: Always bail out when config_attr function fails

perf tools: Always bail out when config_attr function fails

Not sure why we allowed the fail state, but it's wrong.  Wrong type for
'name' term can cause segfault, and there's probably more fun hidden.

Signed-off-by: Jiri Olsa <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>