imxfb: fix memory hole

info->pseudo_palette was previously kmalloced.  Do not overwrite it afterwards

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>