x86: remove unnecessary memset and NULL check after alloc_bootmem()

memset and NULL check after alloc_bootmem() are unnecessary.
Because it returns zeroed memory and it never return NULL.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
1 file changed