Throw exception if dscp value is not byte.

Change-Id: Iae005dda9f28fb28f1bcc9ea5de31f1bf2c65843
diff --git a/core/api/src/main/java/org/onosproject/net/flow/instructions/Instructions.java b/core/api/src/main/java/org/onosproject/net/flow/instructions/Instructions.java
index e0c58d3..d1fc61f 100644
--- a/core/api/src/main/java/org/onosproject/net/flow/instructions/Instructions.java
+++ b/core/api/src/main/java/org/onosproject/net/flow/instructions/Instructions.java
@@ -487,11 +487,11 @@
     /**
      * Creates an IP DSCP modification.
      *
-     * @param dscpValue the DSCP value to modify to
+     * @param ipDscp the DSCP value to modify to
      * @return a L3 modification
      */
-    public static Instruction modIpDscp(byte dscpValue) {
-        return new L3ModificationInstruction.ModDscpInstruction(L3SubType.IP_DSCP, dscpValue);
+    public static Instruction modIpDscp(byte ipDscp) {
+        return new L3ModificationInstruction.ModDscpInstruction(L3SubType.IP_DSCP, ipDscp);
     }
 
     /**