In the perl bindings: Fix a compiler warning about using the result of a
condition without parenthesis.

* subversion/bindings/swig/perl/libsvn-swig_perl/swigutil_pl.c
  (svn_swig_pl_array_to_apr_array_revision_range): Use parens.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1597871 13f79535-47bb-0310-9956-ffa450edef68