futex.2: ffix

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man2/futex.2

@@ -1583,11 +1583,14 @@ fwait(int *futexp)
        the GCC Manual. */
 
     while (1) {
+
         /* Is the futex available? */
+
         if (__sync_bool_compare_and_swap(futexp, 1, 0))
             break;      /* Yes */
 
         /* Futex is not available; wait */
+
         s = futex(futexp, FUTEX_WAIT, 0, NULL, NULL, 0);
         if (s == \-1 && errno != EAGAIN)
             errExit("futex\-FUTEX_WAIT");