perf annotate: Rename 'colors.code' to 'colors.jump_arrows'

perf annotate: Rename 'colors.code' to 'colors.jump_arrows'

USe 'jump_arrows' config name instead of 'code' on 'colors' section.
'colors.code' config is only for jump arrows on assembly code listings
i.e.

    │     ┌──jmp    1333
    │     │  xchg   %ax,%ax
    │     │  mov    %r15,%r10
    │     └─→cmp    %r15,%r14

But this config name seems unfit.

 'jump_arrows' is more descriptive than 'code'.

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1452240971-25418-1-git-send-email-treeze.taeung@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>