fbdev: tdfxfb: fix potential memory leak in tdfxfb_probe()

fbdev: tdfxfb: fix potential memory leak in tdfxfb_probe()

In tdfxfb_probe(), the memory allocated for modelist using
fb_videomode_to_modelist() when CONFIG_FB_3DFX_I2C is defined, is not
freed in the subsequent error paths.
Fix that by calling fb_destroy_modelist().

Fixes: 215059d2421f ("tdfxfb: make use of DDC information about connected monitor")
Cc: stable@vger.kernel.org
Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in>
Signed-off-by: Helge Deller <deller@gmx.de>