Fix problems found by static analysis.

Change-Id: I02c51279f18f629b2d2fb1095692a6ae98b0e25e
diff --git a/src/main/java/eu/mulk/mulkcms2/benki/users/UserRolePK.java b/src/main/java/eu/mulk/mulkcms2/benki/users/UserRolePK.java
index 5649ff4..aca126d 100644
--- a/src/main/java/eu/mulk/mulkcms2/benki/users/UserRolePK.java
+++ b/src/main/java/eu/mulk/mulkcms2/benki/users/UserRolePK.java
@@ -43,11 +43,7 @@
     if (userId != that.userId) {
       return false;
     }
-    if (roleId != that.roleId) {
-      return false;
-    }
-
-    return true;
+    return roleId == that.roleId;
   }
 
   @Override