Fix borked prior commit:

- INADDR, not IFADDR.  Duh.
- Accidentally removed another comment; restored.

This commit was SVN r5070.

include/ompi_config_bottom.h

@@ -235,21 +235,29 @@ extern "C" {
 #endif
 
 /*
- * Define IFADDR_NONE if we don't have it.  Solaris is the only system
+ * Define INADDR_NONE if we don't have it.  Solaris is the only system
  * where I have found that it does not exist, and the man page for
  * inet_addr() says that it returns -1 upon failure.  On Linux and
- * other systems with IFADDR_NONE, it's just a #define to -1 anyway.
+ * other systems with INADDR_NONE, it's just a #define to -1 anyway.
  * So just #define it to -1 here if it doesn't already exist.
  */
 
-#ifndef IFADDR_NONE
-#define IFADDR_NONE -1
+#ifndef INADDR_NONE
+#define INADDR_NONE -1
 #endif
 
 #if defined(c_plusplus) || defined(__cplusplus)
 }
 #endif
 
+/*
+ * Define __func__-preprocessor directive if the compiler does not
+ * already define it.  Define it to __FILE__ so that we at least have
+ * a clue where the developer is trying to indicate where the error is
+ * coming from (assuming that __func__ is typically used for
+ * printf-style debugging).
+ */
+
 #if !HAVE_DECL___FUNC__
 #define __func__ __FILE__
 #endif