fix bug in tester for atom style tri

unittest/formats/test_atom_styles.cpp

@@ -2540,6 +2540,7 @@ TEST_F(AtomStyleTest, tri)
     type   = lmp->atom->type;
     tri    = lmp->atom->tri;
     rmass  = lmp->atom->rmass;
+    radius = lmp->atom->radius;
     avec   = (AtomVecTri *)lmp->atom->avec;
     bonus  = avec->bonus;
     ASSERT_EQ(type[GETIDX(1)], 1);