x86/efi: Fix dummy variable buffer allocation
commit
b8cb62f82103083a6e8fa5470bfe634a2c06514d 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>