avdevice/dshow: Remove unneeded NULL checks

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavdevice/dshow.c

@@ -294,8 +294,7 @@ dshow_cycle_devices(AVFormatContext *avctx, ICreateDevEnum *devenum,
         }
 
 fail1:
-        if (buf)
-            av_free(buf);
+        av_free(buf);
         if (bag)
             IPropertyBag_Release(bag);
         IMoniker_Release(m);
@@ -458,8 +457,7 @@ next:
     }
 end:
     IAMStreamConfig_Release(config);
-    if (caps)
-        av_free(caps);
+    av_free(caps);
     if (pformat_set)
         *pformat_set = format_set;
 }