[svn-r30189] Description:

Clean up more warnings: drop the warning count from ~1310 down to ~940,
with only 31 types of warnings in 148 files (down from 38 types in 167 files).

Tested on:
    MacOSX/64 10.11.5 (amazon) w/serial & parallel
    (h5committest forthcoming)

tools/h5diff/h5diff_main.c

@@ -16,6 +16,7 @@
 #include <stdlib.h>
 #include <assert.h>
 #include <memory.h>
+#include "H5private.h"
 #include "h5diff.h"
 #include "h5diff_common.h"
 #include "h5tools.h"
@@ -136,9 +137,9 @@ int main(int argc, const char *argv[])
  *
  *-------------------------------------------------------------------------
  */
-void
+H5_ATTR_NORETURN void
 h5diff_exit(int status)
 {
-    exit(status);
+    HDexit(status);
 }