Really cleanup after ourselves when creating a repository fails. Without this
patch we leave an incomplete repository on Windows (and we return an ugly
error, which is why I found this problem).

* subversion/libsvn_repos/repos.c
  (svn_repos_create): Use a scratch pool to hold the lock when creating a
    repository to allow destroying the pool when deleting the repository
    on a failure. Rename the normal pool to result_pool.

Found by: SharpSvn test suite


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1581401 13f79535-47bb-0310-9956-ffa450edef68