Fixes tags need work in the smack tree

In commit

be3b23ba4a030 ("Smack: Fix error in capability bypass")

Fixes tag

has these problem(s):

- SHA1 should be at least 12 digits long
This can be fixed for the future by setting core.abbrev to 12 (or more) or (for git v2.11 or later) just making sure it is not set (or set to "auto").