Update XCTAssertNotEqualStrings and XCTAssertEqualStrings to use %zd.
Update XCTAssertNotEqualStrings and XCTAssertEqualStrings to use %zd.

DELTA=2 (0 added, 0 deleted, 2 changed)
DELTA_BY_EXTENSION=h=2
qokelate/google-toolbox-for-mac,qokelate/google-toolbox-for-mac,qokelate/google-toolbox-for-mac