nfsd41: define nfsd4_set_statp as noop for !CONFIG_NFSD_V4

Fixes following modpost error:
ERROR: "nfsd4_set_statp" [fs/nfsd/nfsd.ko] undefined!
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

include/linux/nfsd/cache.h

@@ -75,6 +75,13 @@ int	nfsd_reply_cache_init(void);
 void	nfsd_reply_cache_shutdown(void);
 int	nfsd_cache_lookup(struct svc_rqst *, int);
 void	nfsd_cache_update(struct svc_rqst *, int, __be32 *);
+
+#ifdef CONFIG_NFSD_V4
 void	nfsd4_set_statp(struct svc_rqst *rqstp, __be32 *statp);
+#else  /* CONFIG_NFSD_V4 */
+static inline void nfsd4_set_statp(struct svc_rqst *rqstp, __be32 *statp)
+{
+}
+#endif /* CONFIG_NFSD_V4 */
 
 #endif /* NFSCACHE_H */