FMC: fix error handling in probe() function

The call to kzalloc() wasn't checked.
The dev_info() message dereferenced freed memory on error.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Alessandro Rubini <rubini@gnudd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>