NFSD: Move documenting comment for nfsd4_process_open2()

Clean up nfsd4_open() by converting a large comment at the only
call site for nfsd4_process_open2() to a kerneldoc comment in
front of that function.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

fs/nfsd/nfs4proc.c

@@ -628,11 +628,7 @@ nfsd4_open(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 		status = nfserr_inval;
 		goto out;
 	}
-	/*
-	 * nfsd4_process_open2() does the actual opening of the file.  If
-	 * successful, it (1) truncates the file if open->op_truncate was
-	 * set, (2) sets open->op_stateid, (3) sets open->op_delegation.
-	 */
+
 	status = nfsd4_process_open2(rqstp, resfh, open);
 	WARN(status && open->op_created,
 	     "nfsd4_process_open2 failed to open newly-created file! status=%u\n",

fs/nfsd/nfs4state.c

@@ -5448,6 +5448,18 @@ static void nfsd4_deleg_xgrade_none_ext(struct nfsd4_open *open,
 	 */
 }
 
+/**
+ * nfsd4_process_open2 - finish open processing
+ * @rqstp: the RPC transaction being executed
+ * @current_fh: NFSv4 COMPOUND's current filehandle
+ * @open: OPEN arguments
+ *
+ * If successful, (1) truncate the file if open->op_truncate was
+ * set, (2) set open->op_stateid, (3) set open->op_delegation.
+ *
+ * Returns %nfs_ok on success; otherwise an nfs4stat value in
+ * network byte order is returned.
+ */
 __be32
 nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_open *open)
 {