drm/mgag200: fix a test in mga_vga_mode_valid()

The parentheses are in the wrong place here so we pass the bits per
pixel as zero.

Fixes: abbee6238775 ("drm/mgag200: Added resolution and bandwidth limits for various G200e products.")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180125142655.GA23885@mwanda

drivers/gpu/drm/mgag200/mgag200_mode.c

@@ -1620,8 +1620,8 @@ static int mga_vga_mode_valid(struct drm_connector *connector,
 			return MODE_VIRTUAL_X;
 		if (mode->vdisplay > 1024)
 			return MODE_VIRTUAL_Y;
-		if (mga_vga_calculate_mode_bandwidth(mode,
-			bpp > (31877 * 1024)))
+		if (mga_vga_calculate_mode_bandwidth(mode, bpp) >
+		    (31877 * 1024))
 			return MODE_BANDWIDTH;
 	} else if (mdev->type == G200_EV &&
 		(mga_vga_calculate_mode_bandwidth(mode, bpp)