headers: Consistent use of typeof and/or __typeof__.

Because of a copy-and-paste error, the Asterisk project was using __typeof
instead of typeof. It works because typeof, __typeof, and __typeof__ are
supported by GCC, but here the escaped variant was not intended. Therefore,
for consistence, we change this to typeof.

Change-Id: I2a962c3e596e882f691a19345445b14571a5f07c

include/asterisk/linkedlists.h

@@ -854,7 +854,7 @@ struct {								\
  */
 #define AST_LIST_REMOVE(head, elm, field)						\
 	({															\
-		__typeof(elm) __elm = (elm);							\
+		typeof(elm) __elm = (elm);								\
 		if (__elm) {											\
 			if ((head)->first == __elm) {						\
 				(head)->first = __elm->field.next;				\