Silence a warning about an address that can never be NULL - libevent needs to deal with the situation where the user may have compiled the code on a system where this function is present, but executes it on one where it isn't. Thus, a compile-time test isn't adequate.

Pushed upstream.

cmr:v1.7.3:reviewer=jsquyres

This commit was SVN r29201.

opal/mca/event/libevent2021/libevent/evutil_rand.c

@@ -70,8 +70,11 @@ ev_arc4random_buf(void *buf, size_t n)
 	 * and fall back otherwise.  (OSX does this using some linker
 	 * trickery.)
 	 */
-	if (arc4random_buf != NULL) {
+        {
+            void* tptr = (void*)arc4random_buf;
+            if (tptr != NULL) {
 		return arc4random_buf(buf, n);
+            }
 	}
 #endif
 	/* Make sure that we start out with b at a 4-byte alignment; plenty