[PATCH v3] status: always show tracking branch even no change

Changes since v2:

 * The return value of function stat_tracking_info() is changed.
   When the current branch and its remote tracking branch point
   to the same commit, will return 1, instead of 0. Because we
   want to report the tracking info for such case.

 * Remove duplicated codes in builtin/branch.c, and make it simpler.

Jiang Xin (1):
  status: always show tracking branch even no change

 builtin/branch.c         | 18 +++++-----------
 remote.c                 | 18 +++++++++++-----
 t/t6040-tracking-info.sh | 54 ++++++++++++++++++++++++++++++++++++++++++++----
 wt-status.c              |  5 +++++
 4 files changed, 73 insertions(+), 22 deletions(-)