media: coda: Add check for kmalloc

[ Upstream commit 6e5e5def ]

As the kmalloc may return NULL pointer,
it should be better to check the return value
in order to avoid NULL poineter dereference,
same as the others.

Fixes: cb1d3a33 ("[media] coda: add CODA7541 JPEG support")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Sasha Levin <sashal@kernel.org>