script/build-libgit2-static.sh: correctly set ROOT
script/build-libgit2-static.sh: correctly set ROOT

The ROOT variable is not being set correctly. Need to use dirname against
$0 as well as only go up one directory instead of two.

libgit2/git2go,libgit2/git2go,clns/git2go,pks-t/git2go,pks-t/git2go,libgit2/git2go,clns/git2go,clns/git2go