Replaced an instance of apr_pool_userdata_setn() with apr_pool_userdata_set()..

the value of "userdata_key" is an address on the stack when compiled with
gcc 2.95.3 on Solaris/Sparc, so storing the address directly in the hash
table is unsafe.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@92497 13f79535-47bb-0310-9956-ffa450edef68