Supress compiler warning

Author: tresf

src/main/cpp/_nix_based/jssc.cpp

@@ -537,7 +537,7 @@ JNIEXPORT jboolean JNICALL Java_jssc_SerialNativeInterface_writeBytes
 /**
  * Waits until 'read()' has something to tell for the specified filedescriptor.
  */
-static void awaitReadReady(JNIEnv*env, jlong fd){
+static void awaitReadReady(JNIEnv*, jlong fd){
 #if HAVE_POLL == 0
     // Alternative impl using 'select' as 'poll' isn't available (or broken).