Fix build on AIX

* src/unlink.c (flush_deferred_unlinks): Avoid possible duplicate case
(if ENOTEMPTY==EEXIST)

src/unlink.c

@@ -127,7 +127,9 @@ flush_deferred_unlinks (bool force)
 		    case EEXIST:
 		      /* OpenSolaris >=10 sets EEXIST instead of ENOTEMPTY
 			 if trying to remove a non-empty directory */
+#if defined ENOTEMPTY && ENOTEMPTY != EEXIST
 		    case ENOTEMPTY:
+#endif
 		      /* Keep the record in list, in the hope we'll
 			 be able to remove it later */
 		      prev = p;