Misc. ./samples typos

Found via `codespell -q 3 --skip="./3rdparty" -I ../opencv-whitelist.txt`

samples/cpp/tutorial_code/TrackingMotion/cornerSubPix_Demo.cpp

@@ -96,7 +96,7 @@ void goodFeaturesToTrack_Demo( int, void* )
   namedWindow( source_window, WINDOW_AUTOSIZE );
   imshow( source_window, copy );
 
-  /// Set the neeed parameters to find the refined corners
+  /// Set the needed parameters to find the refined corners
   Size winSize = Size( 5, 5 );
   Size zeroZone = Size( -1, -1 );
   TermCriteria criteria = TermCriteria( TermCriteria::EPS + TermCriteria::COUNT, 40, 0.001 );