SUNRPC: Change list definition method

The LIST_HEAD macro can both define a linked list and initialize
it in one step. To simplify code, we replace the separate operations
of linked list definition and manual initialization with the LIST_HEAD
macro.

Signed-off-by: Chenguang Zhao <zhaochenguang@kylinos.cn>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>

Author: Chenguang Zhao

net/sunrpc/backchannel_rqst.c

@@ -147,7 +147,7 @@ EXPORT_SYMBOL_GPL(xprt_setup_backchannel);
 int xprt_setup_bc(struct rpc_xprt *xprt, unsigned int min_reqs)
 {
 	struct rpc_rqst *req;
-	struct list_head tmp_list;
+	LIST_HEAD(tmp_list);
 	int i;
 
 	dprintk("RPC:       setup backchannel transport\n");
@@ -163,7 +163,6 @@ int xprt_setup_bc(struct rpc_xprt *xprt, unsigned int min_reqs)
 	 * lock is held on the rpc_xprt struct.  It also makes cleanup
 	 * easier in case of memory allocation errors.
 	 */
-	INIT_LIST_HEAD(&tmp_list);
 	for (i = 0; i < min_reqs; i++) {
 		/* Pre-allocate one backchannel rpc_rqst */
 		req = xprt_alloc_bc_req(xprt);