misc: Use kzalloc() instead of kmalloc() with flag GFP_ZERO.

Use kzalloc instead of manually setting kmalloc
with flag GFP_ZERO since kzalloc sets allocated memory
to zero.

Signed-off-by: Huang Zijiang <huang.zijiang@zte.com.cn>
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Link: https://lore.kernel.org/r/1581501247-5479-1-git-send-email-wang.yi59@zte.com.cn


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>