module_to_cil: fix possible use of uninitialized value

Correct errors like these reported by gcc:

module_to_cil.c: In function ‘block_to_cil’:
module_to_cil.c:229:20: error: ‘attr_list’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
  struct list_node *curr = (*attr_list)->head;

Usages of attr_list_destroy() were called when list_init()
fails.

stack_init() and stack_destroy() also suffered from the
aforementioned issue.

To correct the issue, initialize stack and list variables to
NULL.

Signed-off-by: William Roberts <william.c.roberts@intel.com>
1 file changed