* make sure THREADS_HAVE_DIFFERENT_PIDS is always defined to something

This commit was SVN r5057.

config/ompi_config_threads.m4

@@ -144,6 +144,7 @@ elif test "$THREAD_TYPE" = "posix"; then
 elif test "$THREAD_TYPE" = "none"; then
     AC_DEFINE(OMPI_HAVE_SOLARIS_THREADS, 0)
     AC_DEFINE(OMPI_HAVE_POSIX_THREADS, 0)
+    AC_DEFINE(OMPI_THREADS_HAVE_DIFFERENT_PIDS, 0)
 
     TRHEAD_CFLAGS=
     THREAD_FFLAGS=