Use tabs instead of spaces for indentation

This completes our switch to the Linux kernel coding style. Note that we
still use deeply nested constructs at some places which need to be fixed
up later.

Converted using the `Lindent` script from the Linux kernel code base,
along with some manual fixes.

Signed-off-by: Lukas Fleischer <calcurse@cryptocrack.de>

src/llist_ts.h

@@ -37,9 +37,9 @@
 /* Thread-safe linked lists. */
 typedef struct llist_ts llist_ts_t;
 struct llist_ts {
-  llist_item_t *head;
-  llist_item_t *tail;
-  pthread_mutex_t mutex;
+	llist_item_t *head;
+	llist_item_t *tail;
+	pthread_mutex_t mutex;
 };
 
 /* Initialization and deallocation. */