Revision 1502952

Following up on r1502909, resolve error leak and introduce a wrapper function
to allow returning the original SVN_ERR_CEASE_INVOCATION error chain.

* subversion/libsvn_ra_svn/client.c
  (ra_svn_log): Rename to...
  (perform_ra_svn_log): ... and add outer_error argument.

  (ra_svn_log): New function, call perform_ra_svn_log and
    compose a resulting error.