qcam: viewfinder_gl: Drop duplicate glClearColor()

There's no need to call glClearColor() twice before drawing any GL
content. Drop the first call. This doesn't introduce any functional
change.

While at it, pass floats instead of doubles to glClearColor(), as
required by the function.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

src/apps/qcam/viewfinder_gl.cpp

@@ -533,8 +533,6 @@ void ViewFinderGL::initializeGL()
 	/* Create Vertex Shader */
 	if (!createVertexShader())
 		qWarning() << "[ViewFinderGL]: create vertex shader failed.";
-
-	glClearColor(1.0f, 1.0f, 1.0f, 0.0f);
 }
 
 void ViewFinderGL::doRender()
@@ -821,7 +819,7 @@ void ViewFinderGL::paintGL()
 	}
 
 	if (image_) {
-		glClearColor(0.0, 0.0, 0.0, 1.0);
+		glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
 		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
 		doRender();