Change classes directory in Makefileto fix compilation.
Change classes directory in Makefileto fix compilation.

linux-on-ibm-z/snappy-java,asonipsl/snappy-java,asonipsl/snappy-java,asonipsl/snappy-java,linux-on-ibm-z/snappy-java,asonipsl/snappy-java,linux-on-ibm-z/snappy-java,linux-on-ibm-z/snappy-java,asonipsl/snappy-java,xerial/snappy-java,linux-on-ibm-z/snappy-java,xerial/snappy-java,xerial/snappy-java,xerial/snappy-java