SUNRPC: sunrpc should not explicitly depend on NFS config options

Change explicit references to CONFIG_NFS_V4_1 to implicit ones
Get rid of the unnecessary defines in backchannel_rqst.c and
bc_svc.c: the Makefile takes care of those dependency.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/include/linux/sunrpc/bc_xprt.h b/include/linux/sunrpc/bc_xprt.h
index 0828842..f7f3ce34 100644
--- a/include/linux/sunrpc/bc_xprt.h
+++ b/include/linux/sunrpc/bc_xprt.h
@@ -31,7 +31,7 @@
 #include <linux/sunrpc/xprt.h>
 #include <linux/sunrpc/sched.h>
 
-#ifdef CONFIG_NFS_V4_1
+#ifdef CONFIG_SUNRPC_BACKCHANNEL
 struct rpc_rqst *xprt_alloc_bc_request(struct rpc_xprt *xprt);
 void xprt_free_bc_request(struct rpc_rqst *req);
 int xprt_setup_backchannel(struct rpc_xprt *, unsigned int min_reqs);
@@ -47,7 +47,7 @@
 		return 1;
 	return 0;
 }
-#else /* CONFIG_NFS_V4_1 */
+#else /* CONFIG_SUNRPC_BACKCHANNEL */
 static inline int xprt_setup_backchannel(struct rpc_xprt *xprt,
 					 unsigned int min_reqs)
 {
@@ -62,6 +62,6 @@
 static inline void xprt_free_bc_request(struct rpc_rqst *req)
 {
 }
-#endif /* CONFIG_NFS_V4_1 */
+#endif /* CONFIG_SUNRPC_BACKCHANNEL */
 #endif /* _LINUX_SUNRPC_BC_XPRT_H */