Merge r1327689 from trunk:

For a local variable in a macro, use a name that is less likely to clash
with other variable names.

Submitted by: sf
Reviewed by: rjung, humbedooh, jorton


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1364682 13f79535-47bb-0310-9956-ffa450edef68