Solve compile problem for 4.0.22 on hpita2. (Backport of a 4.1 change)

sql/mysqld.cc:
  Replace 'sete_id(_)' calls by 'setre_id(-1,_)' calls, as the former
  have no prototypes on some platforms. (Backport of a 4.1 change)

sql/mysqld.cc

@@ -1114,14 +1114,14 @@ static void set_effective_user(struct passwd *user_info)
 {
 #if !defined(__WIN__) && !defined(OS2) && !defined(__NETWARE__)
   DBUG_ASSERT(user_info);
-  if (setegid(user_info->pw_gid) == -1)
+  if (setregid((gid_t)-1,user_info->pw_gid) == -1)
   {
-    sql_perror("setegid");
+    sql_perror("setregid");
     unireg_abort(1);
   }  
-  if (seteuid(user_info->pw_uid) == -1)
+  if (setreuid((uid_t)-1,user_info->pw_uid) == -1)
   {
-    sql_perror("seteuid");
+    sql_perror("setreuid");
     unireg_abort(1);
   }
 #endif
@@ -2510,9 +2510,9 @@ You should consider changing lower_case_table_names to 1 or 2",
 #if defined(HAVE_MLOCKALL) && defined(MCL_CURRENT)
   if (locked_in_memory && !getuid())
   {
-    if (seteuid(0) == -1)
+    if (setreuid((uid_t)-1,0) == -1)
     {                        // this should never happen
-      sql_perror("seteuid");
+      sql_perror("setreuid");
       unireg_abort(1);
     }
     if (mlockall(MCL_CURRENT))