fix build error when both OpenNI and OpenNI2 are supported (issue 4918)

modules/videoio/src/cap.cpp

@@ -231,7 +231,7 @@ CV_IMPL CvCapture * cvCreateCameraCapture (int index)
 #ifdef HAVE_OPENNI2
     case CV_CAP_OPENNI2:
         if (!capture)
-            capture = cvCreateCameraCapture_OpenNI(index);
+            capture = cvCreateCameraCapture_OpenNI2(index);
         if (pref) break;
 #endif
 

modules/videoio/src/cap_openni2.cpp

@@ -903,7 +903,7 @@ IplImage* CvCapture_OpenNI2::retrieveFrame( int outputType )
     return image;
 }
 
-CvCapture* cvCreateCameraCapture_OpenNI( int index )
+CvCapture* cvCreateCameraCapture_OpenNI2( int index )
 {
     CvCapture_OpenNI2* capture = new CvCapture_OpenNI2( index );
 

modules/videoio/src/precomp.hpp

@@ -120,6 +120,7 @@ CvCapture* cvCreateFileCapture_MSMF (const char* filename);
 CvVideoWriter* cvCreateVideoWriter_MSMF( const char* filename, int fourcc,
                                         double fps, CvSize frameSize, int is_color );
 CvCapture* cvCreateCameraCapture_OpenNI( int index );
+CvCapture* cvCreateCameraCapture_OpenNI2( int index );
 CvCapture* cvCreateFileCapture_OpenNI( const char* filename );
 CvCapture* cvCreateCameraCapture_Android( int index );
 CvCapture* cvCreateCameraCapture_XIMEA( int index );