tst_QFormLayout: Fix UB (invalid enum value) in several functions

The code coerced a -123 into a QFormLayout::ItemFlags, which, however,
being an enum with enumeration values 0..2, only has valid numerical
values 0..3.

Fix by using 3 as the value to represent the invalid enum value, and
store this in a constant so as not to distribute this magic number
all around the test class.

Change-Id: Ie5e93a69ef5a3acdde43030b022e0cce8aec484d
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>

0 files changed, 0 insertions, 0 deletions