fbdev: metronomefb: fix potential memory leak in metronomefb_probe()

fbdev: metronomefb: fix potential memory leak in metronomefb_probe()

The memory allocated for pagerefs in fb_deferred_io_init() is not freed
on the error path. Fix it by calling fb_deferred_io_cleanup().

Fixes: 56c134f7f1b5 ("fbdev: Track deferred-I/O pages in pageref struct")
Cc: stable@vger.kernel.org
Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>