libf2fs: fix build error on Windows am: 471bb35b42 am: 3249de482b am: fd3d4d9ad4

Original change: https://android-review.googlesource.com/c/platform/external/f2fs-tools/+/1333829

Change-Id: Ic210bf6e24be67cca09e7bcd78f20de3e436a332