RANGER-5498: Use provided saltSize parameter at all places in generateSalt method (apache#860)

Author: vikaskr22

kms/src/main/java/org/apache/hadoop/crypto/key/RangerMasterKey.java

@@ -546,7 +546,7 @@ private byte[] generateSalt(int saltSize) throws Throwable {
         MessageDigest md = MessageDigest.getInstance(mdAlgo);
         byte[] saltGen = md.digest(salt.getBytes());
         byte[] salt = new byte[saltSize];
-        System.arraycopy(saltGen, 0, salt, 0, RangerMasterKey.saltSize);
+        System.arraycopy(saltGen, 0, salt, 0, saltSize);
         return salt;
     }