NFS: Fix a warning in nfs4_async_handle_error

We're not modifying the nfs_server when we call nfs_inc_server_stats and
friends, so allow the compiler to pass 'const' pointers too.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/iostat.h

@@ -19,7 +19,7 @@ struct nfs_iostats {
 	unsigned long		events[__NFSIOS_COUNTSMAX];
 } ____cacheline_aligned;
 
-static inline void nfs_inc_server_stats(struct nfs_server *server,
+static inline void nfs_inc_server_stats(const struct nfs_server *server,
 					enum nfs_stat_eventcounters stat)
 {
 	struct nfs_iostats *iostats;
@@ -31,13 +31,13 @@ static inline void nfs_inc_server_stats(struct nfs_server *server,
 	put_cpu_no_resched();
 }
 
-static inline void nfs_inc_stats(struct inode *inode,
+static inline void nfs_inc_stats(const struct inode *inode,
 				 enum nfs_stat_eventcounters stat)
 {
 	nfs_inc_server_stats(NFS_SERVER(inode), stat);
 }
 
-static inline void nfs_add_server_stats(struct nfs_server *server,
+static inline void nfs_add_server_stats(const struct nfs_server *server,
 					enum nfs_stat_bytecounters stat,
 					unsigned long addend)
 {
@@ -50,7 +50,7 @@ static inline void nfs_add_server_stats(struct nfs_server *server,
 	put_cpu_no_resched();
 }
 
-static inline void nfs_add_stats(struct inode *inode,
+static inline void nfs_add_stats(const struct inode *inode,
 				 enum nfs_stat_bytecounters stat,
 				 unsigned long addend)
 {

fs/nfs/nfs4proc.c

@@ -2756,8 +2756,7 @@ nfs4_async_handle_error(struct rpc_task *task, const struct nfs_server *server)
 			task->tk_status = 0;
 			return -EAGAIN;
 		case -NFS4ERR_DELAY:
-			nfs_inc_server_stats((struct nfs_server *) server,
-						NFSIOS_DELAY);
+			nfs_inc_server_stats(server, NFSIOS_DELAY);
 		case -NFS4ERR_GRACE:
 			rpc_delay(task, NFS4_POLL_RETRY_MAX);
 			task->tk_status = 0;