nfsd4: fix comment and remove unused nfsd4_file fields

A couple fields here were left over from a previous version of a patch,
and are no longer used.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

fs/nfsd/state.h

@@ -367,16 +367,12 @@ struct nfs4_file {
 	struct list_head	fi_delegations;
 	/* One each for O_RDONLY, O_WRONLY, O_RDWR: */
 	struct file *		fi_fds[3];
-	/* One each for O_RDONLY, O_WRONLY: */
-	atomic_t		fi_access[2];
 	/*
-	 * Each open stateid contributes 1 to either fi_readers or
-	 * fi_writers, or both, depending on the open mode.  A
-	 * delegation also takes an fi_readers reference.  Lock
-	 * stateid's take none.
+	 * Each open or lock stateid contributes 1 to either
+	 * fi_access[O_RDONLY], fi_access[O_WRONLY], or both, depending
+	 * on open or lock mode:
 	 */
-	atomic_t		fi_readers;
-	atomic_t		fi_writers;
+	atomic_t		fi_access[2];
 	struct file		*fi_deleg_file;
 	struct file_lock	*fi_lease;
 	atomic_t		fi_delegees;