Fix error handling in cmdline stdio function.s.
Fix error handling in cmdline stdio function.s.

* libsvn_subr/cmdline.c (svn_cmdline_fputs, svn_cmdline_fflush): Use errno
instead of apr_{set,get}_os_error(), which hopefully works on Win32.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion