Silence gcc warning about rv being used when possibly uninitialized. That

can only happen if n<=1 (ie, a bad parameter value), so I figure APR_EINVAL
is the correct default value.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@89333 13f79535-47bb-0310-9956-ffa450edef68