The perf_config() infrastructure we inherited from git calls die() when
the provided config callback returns -1, meaning some key in a config
section is unexpected, that seems ok for a stdio based tool, but in
--tui we end up messing up the output, so just tell the user about the
error, wait for a keystroke and return 0, being more resilient and
proceeding with what we managed to parse.

That die() needs to die, tho :-)

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-pqtsffh2kwr5mwm4qg9kgotu@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>