coverity#1000506 Unchecked return value

Change-Id: I71e824e7f0e279582f12d5cb9443a4177551a705
Resolves: fdo#53029 1~ instead of ~1 and 10~ instead of 1~0

regression from 3351ebde48a31173c2fea9f7270224017e1f4412
Date:   Sat Mar 29 22:22:42 2014 +0100
    OUString: remove temporaries and repeated expressions

but understandable as it was unreadable goo originally

Change-Id: I3ce161bd2628f3a49b14df886ee8d684b248db1c