made handling of _oserror and errno consistent. git-svn-id: svn://svn.cc65.org/cc65/trunk@4731 b7a2c559-68d2-44c3-8de9-860c34a00d81
made handling of _oserror and errno consistent. git-svn-id: svn://svn.cc65.org/cc65/trunk@4731 b7a2c559-68d2-44c3-8de9-860c34a00d81