eliminate redundant classpath creation

Patch by eevans; reviewed by Anton Winter for CASSANDRA-6101

debian/cassandra.in.sh

@@ -18,3 +18,5 @@ done
 for jar in /usr/share/cassandra/*.jar; do
     CLASSPATH=$CLASSPATH:$jar
 done
+
+CLASSPATH="$CLASSPATH:$EXTRA_CLASSPATH"

debian/init

@@ -77,26 +77,9 @@ fi
 # Depend on lsb-base (>= 3.0-6) to ensure that this file is present.
 . /lib/lsb/init-functions
 
+# If JNA is installed, add it to EXTRA_CLASSPATH
 #
-# Function that returns the applications classpath
-#
-classpath()
-{
-    cp="$EXTRA_CLASSPATH"
-    for j in /usr/share/$NAME/lib/*.jar; do
-        [ "x$cp" = "x" ] && cp=$j || cp=$cp:$j
-    done
-    for j in /usr/share/$NAME/*.jar; do
-        [ "x$cp" = "x" ] && cp=$j || cp=$cp:$j
-    done
-
-    # use JNA if installed in standard location
-    [ -r /usr/share/java/jna.jar ] && cp="$cp:/usr/share/java/jna.jar"
-
-    # Include the conf directory for purposes of log4j-server.properties, and
-    # commons-daemon in support of the daemonization class.
-    printf "$cp:$CONFDIR:/usr/share/java/commons-daemon.jar"
-}
+EXTRA_CLASSPATH="/usr/share/java/jna.jar:$EXTRA_CLASSPATH"
 
 #
 # Function that returns 0 if process is running, or nonzero if not.
@@ -136,6 +119,8 @@ do_start()
     [ -e `dirname "$PIDFILE"` ] || \
         install -d -ocassandra -gcassandra -m750 `dirname $PIDFILE`
 
+    export EXTRA_CLASSPATH
+
     start-stop-daemon -S -c cassandra -a /usr/sbin/cassandra -q -p "$PIDFILE" -t >/dev/null || return 1
 
     start-stop-daemon -S -c cassandra -a /usr/sbin/cassandra -b -p "$PIDFILE" -- \