(sctp) fatal warnings overly restrictive with gcc 4.8.1

The SCTP native code complies with -Werror. gcc 4.8.1 reports unused parameters as warnings, and this causes the build to fail. gcc 4.8.1 is the defaul on Ubuntu 13.10.

<snippet of the bottom of the build log>
....
/home/chhegar/repos/jdk8/build/jdk/src/solaris/native/sun/nio/ch/sctp/SctpChannelImpl.c: In function ‘Java_sun_nio_ch_sctp_SctpChannelImpl_receive0’:
/home/chhegar/repos/jdk8/build/jdk/src/solaris/native/sun/nio/ch/sctp/SctpChannelImpl.c:416:24: error: unused parameter ‘klass’ [-Werror=unused-parameter]
   (JNIEnv *env, jclass klass, jint fd, jobject resultContainerObj,
                        ^
/home/chhegar/repos/jdk8/build/jdk/src/solaris/native/sun/nio/ch/sctp/SctpChannelImpl.c: In function ‘Java_sun_nio_ch_sctp_SctpChannelImpl_send0’:
/home/chhegar/repos/jdk8/build/jdk/src/solaris/native/sun/nio/ch/sctp/SctpChannelImpl.c:506:24: error: unused parameter ‘klass’ [-Werror=unused-parameter]
   (JNIEnv *env, jclass klass, jint fd, jlong address, jint length,
                        ^
cc1: all warnings being treated as errors
make[2]: *** [/home/chhegar/repos/jdk8/build/build/linux-x86_64-normal-server-release/jdk/objs/libsctp/SctpChannelImpl.o] Error 1
make[2]: *** Waiting for unfinished jobs....
make[1]: *** [libs-only] Error 2
make: *** [jdk-only] Error 2