"git status --branch --short" accessed beyond the constant string
"HEAD", which has been corrected.
* rs/wt-status-detached-branch-fix:
wt-status: use skip_prefix() to get rid of magic string length constants
wt-status: don't skip a magical number of characters blindly
wt-status: avoid building bogus branch name with detached HEAD
wt-status: exit early using goto in wt_shortstatus_print_tracking()
t7060: add test for status --branch on a detached HEAD