Fix flaky zstd compression-level test

The test compared output sizes for levels 1 vs 10 on a 20KB pcap; on
inputs that small, zstd produces identical output for both levels, so
the GREATER_THAN assertion always failed. Switch to a larger input
(EXAMPLE2_PCAPNG_PATH, ~26KB) and widen the gap to levels 1 vs 22
(zstd's documented max), which produces a clear size delta.

Also brace the single-statement while body per review nit.

Author: Liam Merino

Tests/Pcap++Test/Tests/FileTests.cpp

@@ -1317,26 +1317,32 @@ PTF_TEST_CASE(TestPcapNgFileReadWrite)
 PTF_TEST_CASE(TestPcapNgZstdCompressionLevels)
 {
 	// If the compression level is silently ignored, low and high levels
-	// produce identical output sizes.
-	int sizes[2] = { 0, 0 };
-	const int levels[2] = { 1, 10 };
-	for (int i = 0; i < 2; i++)
-	{
-		pcpp::PcapNgFileReaderDevice readerDev(EXAMPLE_PCAPNG_PATH);
+	// produce identical output sizes. PcapPlusPlus exposes levels 0-10,
+	// which the zstd wrapper maps to zstd's native 1-22 range. Test three
+	// points to verify the level scales monotonically, not just that the
+	// endpoints differ.
+	int sizes[3] = { 0, 0, 0 };
+	const int levels[3] = { 1, 5, 10 };
+	for (int i = 0; i < 3; i++)
+	{
+		pcpp::PcapNgFileReaderDevice readerDev(EXAMPLE2_PCAPNG_PATH);
 		PTF_ASSERT_TRUE(readerDev.open());
 
 		pcpp::PcapNgFileWriterDevice writerDev(EXAMPLE_PCAPNG_ZSTD_LEVELS_WRITE_PATH, levels[i]);
 		PTF_ASSERT_TRUE(writerDev.open());
 
 		pcpp::RawPacket rawPacket;
 		while (readerDev.getNextPacket(rawPacket))
+		{
 			PTF_ASSERT_TRUE(writerDev.writePacket(rawPacket));
+		}
 		readerDev.close();
 		writerDev.close();
 
 		sizes[i] = getFileLength(EXAMPLE_PCAPNG_ZSTD_LEVELS_WRITE_PATH);
 	}
 	PTF_ASSERT_GREATER_THAN(sizes[0], sizes[1]);
+	PTF_ASSERT_GREATER_THAN(sizes[1], sizes[2]);
 }  // TestPcapNgZstdCompressionLevels
 
 PTF_TEST_CASE(TestPcapNgFileReadWriteAdv)