Remove useless checks for NULL before freeing

Remove useless checks for NULL before freeing

Same as earlier commit, except for "FREE"

This patch has been generated by the following Coccinelle semantic
patch:

// Remove useless checks for NULL before freeing
//
// free (NULL) is a no-op, so there is no need to avoid it

@@
expression E;
@@
+ FREE (E);
+ E = NULL;
- if (unlikely (E != NULL)) {
-   FREE(E);
(
-   E = NULL;
|
-   E = 0;
)
   ...
- }

@@
expression E;
type T;
@@
+ FREE ((T) E);
+ E = NULL;
- if (unlikely (E != NULL)) {
-   FREE((T) E);
(
-   E = NULL;
|
-   E = 0;
)
   ...
- }

@@
expression E;
@@
+ FREE (E);
- if (unlikely (E != NULL)) {
-   FREE (E);
- }

@@
expression E;
type T;
@@
+ FREE ((T) E);
- if (unlikely (E != NULL)) {
-   FREE ((T) E);
- }

Reviewed-by: Brian Paul <brianp@vmware.com>