Fix how getRepeatedFieldArrayLength works

Change-Id: I01921eff008a8e3f7b1fbeb653d15ff8038d3220

java/src/main/java/com/google/protobuf/nano/WireFormatNano.java

@@ -113,11 +113,7 @@ public final class WireFormatNano {
     int arrayLength = 1;
     int startPos = input.getPosition();
     input.skipField(tag);
-    while (input.getBytesUntilLimit() > 0) {
-      int thisTag = input.readTag();
-      if (thisTag != tag) {
-        break;
-      }
+    while (input.readTag() == tag) {
       input.skipField(tag);
       arrayLength++;
     }