Fix sys-queue.h conflict for good

Problem: Our file sys-queue.h is a copy of the BSD file, but there are
some additions and it's not entirely compatible. Because of that, there have
been conflicts with system headers on BSD systems. Some hacks have been
introduced in the commits 15cc9235840a22c289edbe064a9b3c19c5f49896,
f40d753718c72693c5f520f0d9899f6e50395e94,
96555a96d724016e13190b28cffa3bc929ac60dc and
3990d09adf4463eca200ad964cc55643c33feb50 but the fixes were fragile.

Solution: Avoid the conflict entirely by renaming the functions and the
file. Revert the previous hacks.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
diff --git a/aio.c b/aio.c
index efc63fd..da18443 100644
--- a/aio.c
+++ b/aio.c
@@ -13,13 +13,13 @@
 
 #include "qemu-common.h"
 #include "block.h"
-#include "sys-queue.h"
+#include "qemu-queue.h"
 #include "qemu_socket.h"
 
 typedef struct AioHandler AioHandler;
 
 /* The list of registered AIO handlers */
-static LIST_HEAD(, AioHandler) aio_handlers;
+static QLIST_HEAD(, AioHandler) aio_handlers;
 
 /* This is a simple lock used to protect the aio_handlers list.  Specifically,
  * it's used to ensure that no callbacks are removed while we're walking and
@@ -35,14 +35,14 @@
     AioFlushHandler *io_flush;
     int deleted;
     void *opaque;
-    LIST_ENTRY(AioHandler) node;
+    QLIST_ENTRY(AioHandler) node;
 };
 
 static AioHandler *find_aio_handler(int fd)
 {
     AioHandler *node;
 
-    LIST_FOREACH(node, &aio_handlers, node) {
+    QLIST_FOREACH(node, &aio_handlers, node) {
         if (node->fd == fd)
             if (!node->deleted)
                 return node;
@@ -72,7 +72,7 @@
                  * deleted because deleted nodes are only cleaned up after
                  * releasing the walking_handlers lock.
                  */
-                LIST_REMOVE(node, node);
+                QLIST_REMOVE(node, node);
                 qemu_free(node);
             }
         }
@@ -81,7 +81,7 @@
             /* Alloc and insert if it's not already there */
             node = qemu_mallocz(sizeof(AioHandler));
             node->fd = fd;
-            LIST_INSERT_HEAD(&aio_handlers, node, node);
+            QLIST_INSERT_HEAD(&aio_handlers, node, node);
         }
         /* Update handler with latest information */
         node->io_read = io_read;
@@ -109,7 +109,7 @@
 	 */
         qemu_aio_wait();
 
-        LIST_FOREACH(node, &aio_handlers, node) {
+        QLIST_FOREACH(node, &aio_handlers, node) {
             ret |= node->io_flush(node->opaque);
         }
     } while (qemu_bh_poll() || ret > 0);
@@ -133,7 +133,7 @@
         FD_ZERO(&wrfds);
 
         /* fill fd sets */
-        LIST_FOREACH(node, &aio_handlers, node) {
+        QLIST_FOREACH(node, &aio_handlers, node) {
             /* If there aren't pending AIO operations, don't invoke callbacks.
              * Otherwise, if there are no AIO requests, qemu_aio_wait() would
              * wait indefinitely.
@@ -168,7 +168,7 @@
 
             /* we have to walk very carefully in case
              * qemu_aio_set_fd_handler is called while we're walking */
-            node = LIST_FIRST(&aio_handlers);
+            node = QLIST_FIRST(&aio_handlers);
             while (node) {
                 AioHandler *tmp;
 
@@ -184,10 +184,10 @@
                 }
 
                 tmp = node;
-                node = LIST_NEXT(node, node);
+                node = QLIST_NEXT(node, node);
 
                 if (tmp->deleted) {
-                    LIST_REMOVE(tmp, node);
+                    QLIST_REMOVE(tmp, node);
                     qemu_free(tmp);
                 }
             }