Fix tabs and spaces problems

NIH-Chest-X-ray-dataset.py

@@ -118,11 +118,11 @@ class ChestXray14(datasets.GeneratorBasedBuilder):
 		        "image": datasets.Image(),
   		        "labels": datasets.features.Sequence(
                                      datasets.features.ClassLabel(
-					num_classes=len(_NAMES),
-					names=_NAMES
-			  	     )
-	    	                  )
-		    )
+                                        num_classes=len(_NAMES),
+                                        names=_NAMES
+                                     )
+                                 )
+                    )
 		    keys = ("image", "labels")
 
 		return datasets.DatasetInfo(