katatestutils: Reset TestConstraints fields on NotValid() call

`TestConstraint.NotValid()` is really designed to be called once per
test. However, there is no reason it should not be possible to call
multiple times. But to allow for that secenario, any settings
from a previous `NotValid()` call need to be cleared.

Signed-off-by: James O. D. Hunt <james.o.hunt@intel.com>

pkg/katatestutils/constraints_api.go

@@ -112,6 +112,11 @@ func (tc *TestConstraint) NotValid(constraints ...Constraint) bool {
 		panic("need atleast one constraint")
 	}
 
+	// Reset in case of a previous call
+	tc.Passed = nil
+	tc.Failed = nil
+	tc.Issue = ""
+
 	for _, c := range constraints {
 		invalid := tc.constraintInvalid(c)
 		if invalid {