Somehow the check for the specific value "external" got dropped in the

logic (even though the "else" clause for handling it was there).  This
commit puts back the specific check for the word "external".

Thanks to Jed Brown for noticing the issue.  Fixes trac:2503.

This commit was SVN r23475.

The following Trac tickets were found above:
  Ticket 2503 --> https://svn.open-mpi.org/trac/ompi/ticket/2503

opal/mca/paffinity/hwloc/configure.m4

@@ -96,7 +96,7 @@ AC_DEFUN([MCA_paffinity_hwloc_CONFIG],[
 
     # If we are not building internal, then run all the normal checks
     AS_IF([test "$paffinity_hwloc_location" != "internal" -a "$paffinity_hwloc_location" != "no"],
-          [AS_IF([test ! -z "$paffinity_hwloc_location" -a "$paffinity_hwloc_location" != "yes"],
+          [AS_IF([test ! -z "$paffinity_hwloc_location" -a "$paffinity_hwloc_location" != "yes" -a "$paffinity_hwloc_location" != "external"],
                  [opal_check_hwloc_dir=$paffinity_hwloc_location
                   AC_MSG_RESULT([external install ($paffinity_hwloc_location)])],
                  [AC_MSG_RESULT([external install (default search paths)])])