commit b8cb62f8 upstream.

1. Check for allocation failure
2. Clear the buffer contents, as they may actually be written to flash
3. Don't leak the buffer

Compile-tested only.

[ Tested successfully on my buggy ASUS machine - Matt ]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Cc: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>