Fix bug in test_tiff.cpp

The big endian data in the tiff_sample_data array was never being tested.  This could be observed by e.g. changing the 9th byte in the big endian data from 0xde to something that should fail the test, e.g. 0xdd, and the test would still pass even though it should fail.

modules/imgcodecs/test/test_tiff.cpp

@@ -76,7 +76,7 @@ TEST(Imgcodecs_Tiff, write_read_16bit_big_little_endian)
         // Write sample TIFF file
         FILE* fp = fopen(filename.c_str(), "wb");
         ASSERT_TRUE(fp != NULL);
-        ASSERT_EQ((size_t)1, fwrite(tiff_sample_data, 86, 1, fp));
+        ASSERT_EQ((size_t)1, fwrite(tiff_sample_data[i], 86, 1, fp));
         fclose(fp);
 
         Mat img = imread(filename, IMREAD_UNCHANGED);