It was inconvenient that perf cannot be quit with SIGINT during
processing samples on TUI especially for large data files.

This was because the first argument of SLang_init_tty(), abort_char,
being 0.  The manual says it's the ascii value of the control character
that will be used to generate the interrupt signal [1].  Passing -1
means to use the default value (Ctrl-C).

However, after processing samples, Ctrl-C was used to in other cases as
well - like stepping back from annotate.  So recover the original
behavior after processing.

[1] http://jedsoft.org/slang/doc/html/cslang-6.html#ss6.1Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1432904024-13170-1-git-send-email-namhyung@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>