minor refactor

Author: dghgit

core/src/main/java/org/bouncycastle/crypto/digests/SHAKEDigest.java

@@ -50,16 +50,11 @@ public int doFinal(byte[] out, int outOff)
 
     public int doFinal(byte[] out, int outOff, int outLen)
     {
-        if (!squeezing)
-        {
-            absorb(new byte[]{0x0F}, 0, 4);
-        }
-
-        squeeze(out, outOff, ((long)outLen) * 8);
+        int length = doOutput(out, outOff, outLen);
 
         reset();
 
-        return outLen;
+        return length;
     }
 
     public int doOutput(byte[] out, int outOff, int outLen)