Call apr_file_write_full instead to achieve the same effect.

apr_file_write_full is *guaranteed* to either write everything or return
an error.  It'll only write short if it received an error.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@95371 13f79535-47bb-0310-9956-ffa450edef68