eldbus: don't abs() an unsigned value

clang complained about abs() being used on an unsigned integer.
Calling abs() is actually unnecessary.

src/examples/eldbus/complex-types-client-eina-value.c

@@ -31,7 +31,7 @@ _type_offset(unsigned base, unsigned size)
    unsigned padding;
    if (!(base % size))
      return base;
-   padding = abs(base - size);
+   padding = base - size;
    return base + padding;
 }