Bug #3201 fix

modules/highgui/src/cap_dshow.cpp

@@ -3164,18 +3164,18 @@ void CvCaptureCAM_DShow::close()
 // Initialize camera input
 bool CvCaptureCAM_DShow::open( int _index )
 {
-    int try_index = _index;
     int devices = 0;
 
     close();
     devices = VI.listDevices(true);
     if (devices == 0)
         return false;
-    try_index = try_index < 0 ? 0 : (try_index > devices-1 ? devices-1 : try_index);
-    VI.setupDevice(try_index);
-    if( !VI.isDeviceSetup(try_index) )
+	if (_index < 0 || index > devices-1)
+		return false;
+    VI.setupDevice(_index);
+    if( !VI.isDeviceSetup(_index) )
         return false;
-    index = try_index;
+    index = _index;
     return true;
 }