Use os_zalloc() instead of os_malloc() and os_memset()

Use os_zalloc() instead of os_malloc() and os_memset()

Automatically updated with spatch and the following semantic patch:

@@
expression X;
expression E1;
statement S;
@@

- X = os_malloc(E1);
+ X = os_zalloc(E1);
(
  if (X == NULL) {
	...
  }
- os_memset(X, 0, E1);
|
  if (X == NULL)
	S
- os_memset(X, 0, E1);
)

Signed-off-by: Jouni Malinen <j@w1.fi>