reduce use of UniString ctor from null-terminated unicodearray

Change-Id: I98361309ada084d8f78517ce88f210d785f59cc0

basic/source/classes/image.cxx

@@ -480,12 +480,9 @@ String SbiImage::GetString( short nId ) const
             }
         }
         else
-        {
-            String aStr( pStr );
-            return aStr;
-        }
+            return rtl::OUString(pStr);
     }
-    return String();
+    return rtl::OUString();
 }
 
 const SbxObject* SbiImage::FindType (String aTypeName) const

basic/source/sbx/sbxexec.cxx

@@ -153,7 +153,7 @@ static SbxVariable* Operand
     {
         // A number could be scanned in directly!
         sal_uInt16 nLen;
-        if( !refVar->Scan( XubString( p ), &nLen ) )
+        if( !refVar->Scan( rtl::OUString( p ), &nLen ) )
             refVar.Clear();
         else
             p += nLen;