Checkstyle/client/first round

Since it is taking too long, I will make a second pr for the rest to make merge process easier. 
Just return, there is no point in stuffing it in a local variable and returning at the end.

Just suppress the return count for this method. Normally for serialization I get these suppressions:

```
   <!-- current.atomiclong-->
    <suppress checks="MethodCount" files="com.hazelcast.concurrent.atomiclong.AtomicLongProxy"/>
    <suppress checks="ReturnCount" files="com.hazelcast.concurrent.atomiclong.client.AtomicLongPortableHook"/>
    <suppress checks="ReturnCount" files="com.hazelcast.concurrent.atomiclong.AtomicLongDataSerializerHook"/>
    <suppress checks="CyclomaticComplexity" files="com.hazelcast.concurrent.atomiclong.AtomicLongDataSerializerHook"/>
    <suppress checks="AnonInnerLength" files="com.hazelcast.concurrent.atomiclong.AtomicLongDataSerializerHook"/>
```