Following up on r1562072, rename some internal functions and argument names
to match the stream api and to avoid some warnings on shadowing names. No
functional changes.

* subversion/libsvn_ra_svn/cyrus_auth.c
  (sasl_pending_cb): Rename to...
  (sasl_data_available_cb): ... and rename argument.
  (svn_ra_svn__enable_sasl_encryption): Update reference.

* subversion/libsvn_ra_svn/editorp.c
  (check_for_error_internal): Rename variable. Update caller.

* subversion/libsvn_ra_svn/marshal.c
  (svn_ra_svn__input_waiting): Rename to...
  (svn_ra_svn__data_available): ... this. Update caller.
  (svn_ra_svn__has_item): Update caller.

* subversion/libsvn_ra_svn/ra_svn.h
  (svn_ra_svn__input_waiting): Rename to...
  (svn_ra_svn__data_available): ... this.

  (svn_ra_svn__stream_pending): Rename to...
  (svn_ra_svn__stream_data_available): ... this.

* subversion/libsvn_ra_svn/streams.c
  (svn_ra_svn__stream_pending): Rename to...
  (svn_ra_svn__stream_data_available): ... this.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1562088 13f79535-47bb-0310-9956-ffa450edef68