NFS: Fix up the declaration of nfs4_restart_rpc when NFSv4 not configured

Also rename it: it is used in generic code, and so should not have a 'nfs4'
prefix.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/internal.h

@@ -197,7 +197,6 @@ extern const u32 nfs41_maxwrite_overhead;
 #endif
 
 /* nfs4proc.c */
-extern void nfs4_restart_rpc(struct rpc_task *, const struct nfs_client *);
 #ifdef CONFIG_NFS_V4
 extern struct rpc_procinfo nfs4_procedures[];
 #endif
@@ -367,3 +366,15 @@ unsigned int nfs_page_array_len(unsigned int base, size_t len)
 	return ((unsigned long)len + (unsigned long)base +
 		PAGE_SIZE - 1) >> PAGE_SHIFT;
 }
+
+/*
+ * Helper for restarting RPC calls in the possible presence of NFSv4.1
+ * sessions.
+ */
+static inline void nfs_restart_rpc(struct rpc_task *task, const struct nfs_client *clp)
+{
+	if (nfs4_has_session(clp))
+		rpc_restart_call_prepare(task);
+	else
+		rpc_restart_call(task);
+}