update GETTING_STARTED.md (#739)

update init_detector() & inference_detector() parameter

GETTING_STARTED.md

@@ -68,7 +68,7 @@ config_file = 'configs/faster_rcnn_r50_fpn_1x.py'
 checkpoint_file = 'checkpoints/faster_rcnn_r50_fpn_1x_20181010-3d1b3351.pth'
 
 # build the model from a config file and a checkpoint file
-model = init_detector(config_file, checkpoint_file)
+model = init_detector(config_file, checkpoint_file, device='cuda:0'))
 
 # test a single image and show the results
 img = 'test.jpg'  # or img = mmcv.imread(img), which will only load it once
@@ -77,7 +77,7 @@ show_result(img, result, model.CLASSES)
 
 # test a list of images and write the results to image files
 imgs = ['test1.jpg', 'test2.jpg']
-for i, result in enumerate(inference_detector(model, imgs, device='cuda:0')):
+for i, result in enumerate(inference_detector(model, imgs):
     show_result(imgs[i], result, model.CLASSES, out_file='result_{}.jpg'.format(i))
 ```