[#3375] Correctly calculate the endOffset when wrap multiple ByteBuffer

Motivation:

We failed to correctly calculate the endOffset when wrap multiple ByteBuffer and so not wrapped everything when an offset > 0 is used.

Modifications:

Correctly calculate endOffset.

Result:

All ByteBuffers are correctly wrapped when offset > 0.

handler/src/main/java/io/netty/handler/ssl/OpenSslEngine.java

@@ -427,7 +427,8 @@ public final class OpenSslEngine extends SSLEngine {
 
         // There was no pending data in the network BIO -- encrypt any application data
         int bytesConsumed = 0;
-        for (int i = offset; i < length; ++ i) {
+        int endOffset = offset + length;
+        for (int i = offset; i < endOffset; ++ i) {
             final ByteBuffer src = srcs[i];
             while (src.hasRemaining()) {