5704 libzfs can only handle 255 filedescriptors

@@ -522,5 +522,10 @@
     'zvol_misc_004_pos', 'zvol_misc_005_neg', 'zvol_misc_006_pos']
 
 [/opt/zfs-tests/tests/functional/zvol/zvol_swap]
 tests = ['zvol_swap_001_pos', 'zvol_swap_002_pos', 'zvol_swap_003_pos',
     'zvol_swap_004_pos', 'zvol_swap_005_pos', 'zvol_swap_006_pos']
+
+[/opt/zfs-tests/tests/functional/libzfs]
+tests = ['many_fds']
+pre =
+post =