ext4: remove unnecessary test_opt for DIOREAD_NOLOCK

The DIOREAD_NOLOCK flag has been cleared when doing the test_opt
that is meaningless, so remove the unnecessary test_opt for DIOREAD_NOLOCK.

Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Link: https://lore.kernel.org/r/1586751862-19437-1-git-send-email-kaixuxia@tencent.com


Signed-off-by: Theodore Ts'o <tytso@mit.edu>