tests: correct skipif sense (#2931)

Co-authored-by: Martin Mokry <martin-kokos@users.noreply.github.com>
(cherry picked from commit 6438cd5)

Author: martin-kokos

tests/unittests/detection/test_map.py

@@ -62,7 +62,9 @@ def _generate_coco_inputs(iou_type):
 _coco_segm_input = _generate_coco_inputs("segm")
 
 
-@pytest.mark.skipif(_PYCOCOTOOLS_AVAILABLE, reason="test requires that torchvision=>0.8.0 and pycocotools is installed")
+@pytest.mark.skipif(
+    not _PYCOCOTOOLS_AVAILABLE, reason="test requires that torchvision=>0.8.0 and pycocotools is installed"
+)
 @pytest.mark.parametrize("iou_type", ["bbox", "segm"])
 @pytest.mark.parametrize("backend", ["pycocotools", "faster_coco_eval"])
 def test_tm_to_coco(tmpdir, iou_type, backend):
@@ -172,7 +174,9 @@ def _compare_against_coco_fn(preds, target, iou_type, iou_thresholds=None, rec_t
     }
 
 
-@pytest.mark.skipif(_PYCOCOTOOLS_AVAILABLE, reason="test requires that torchvision=>0.8.0 and pycocotools is installed")
+@pytest.mark.skipif(
+    not _PYCOCOTOOLS_AVAILABLE, reason="test requires that torchvision=>0.8.0 and pycocotools is installed"
+)
 @pytest.mark.parametrize("iou_type", ["bbox", "segm"])
 @pytest.mark.parametrize("ddp", [pytest.param(True, marks=pytest.mark.DDP), False])
 @pytest.mark.parametrize("backend", ["pycocotools", "faster_coco_eval"])
@@ -447,7 +451,9 @@ def _generate_random_segm_input(device, batch_size=2, num_preds_size=10, num_gt_
     return preds, targets
 
 
-@pytest.mark.skipif(_PYCOCOTOOLS_AVAILABLE, reason="test requires that torchvision=>0.8.0 is installed")
+@pytest.mark.skipif(
+    not _PYCOCOTOOLS_AVAILABLE, reason="test requires that torchvision=>0.8.0 and pycocotools is installed"
+)
 @pytest.mark.parametrize(
     "backend",
     [