NFS: constify nfs_server_capable() and nfs_have_writebacks()

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

include/linux/nfs_fs.h

@@ -363,7 +363,7 @@ static inline void nfs_mark_for_revalidate(struct inode *inode)
 	spin_unlock(&inode->i_lock);
 }
 
-static inline int nfs_server_capable(struct inode *inode, int cap)
+static inline int nfs_server_capable(const struct inode *inode, int cap)
 {
 	return NFS_SERVER(inode)->caps & cap;
 }
@@ -587,12 +587,11 @@ extern struct nfs_commit_data *nfs_commitdata_alloc(bool never_fail);
 extern void nfs_commit_free(struct nfs_commit_data *data);
 bool nfs_commit_end(struct nfs_mds_commit_info *cinfo);
 
-static inline int
-nfs_have_writebacks(struct inode *inode)
+static inline bool nfs_have_writebacks(const struct inode *inode)
 {
 	if (S_ISREG(inode->i_mode))
 		return atomic_long_read(&NFS_I(inode)->nrequests) != 0;
-	return 0;
+	return false;
 }
 
 /*