This is a more concise approach and guarantees there is
no time window where the struct is uninitialized.

Generated using the following semantic patch:

  @@
  type T;
  identifier X;
  @@
  -  T X;
  +  T X = { 0 };
     ... when exists
  (
  -  memset(&X, 0, sizeof(X));
  |
  -  memset(&X, 0, sizeof(T));
  )

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Claudio Fontana <cfontana@suse.de>