nfs: Fix fall-through warnings for Clang

In preparation to enable -Wimplicit-fallthrough for Clang, fix multiple
warnings by explicitly add multiple break/goto/return/fallthrough
statements instead of just letting the code fall through to the next
case.

Link: https://github.com/KSPP/linux/issues/115Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs/nfs3acl.c

@@ -111,6 +111,7 @@ struct posix_acl *nfs3_get_acl(struct inode *inode, int type)
 			fallthrough;
 		case -ENOTSUPP:
 			status = -EOPNOTSUPP;
+			goto getout;
 		default:
 			goto getout;
 	}

fs/nfs/nfs4client.c

@@ -609,6 +609,7 @@ int nfs40_walk_client_list(struct nfs_client *new,
 			 * changed. Schedule recovery!
 			 */
 			nfs4_schedule_path_down_recovery(pos);
+			goto out;
 		default:
 			goto out;
 		}

fs/nfs/nfs4proc.c

@@ -2227,6 +2227,7 @@ static int nfs4_handle_delegation_recall_error(struct nfs_server *server, struct
 		default:
 			printk(KERN_ERR "NFS: %s: unhandled error "
 					"%d.\n", __func__, err);
+			fallthrough;
 		case 0:
 		case -ENOENT:
 		case -EAGAIN:
@@ -9701,6 +9702,7 @@ nfs4_layoutcommit_done(struct rpc_task *task, void *calldata)
 	case -NFS4ERR_BADLAYOUT:     /* no layout */
 	case -NFS4ERR_GRACE:	    /* loca_recalim always false */
 		task->tk_status = 0;
+		break;
 	case 0:
 		break;
 	default:

fs/nfs/nfs4state.c

@@ -1125,6 +1125,7 @@ static void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
 					" sequence-id error on an"
 					" unconfirmed sequence %p!\n",
 					seqid->sequence);
+			return;
 		case -NFS4ERR_STALE_CLIENTID:
 		case -NFS4ERR_STALE_STATEID:
 		case -NFS4ERR_BAD_STATEID:

fs/nfs/pnfs.c

@@ -2875,6 +2875,7 @@ pnfs_do_write(struct nfs_pageio_descriptor *desc,
 	switch (trypnfs) {
 	case PNFS_NOT_ATTEMPTED:
 		pnfs_write_through_mds(desc, hdr);
+		break;
 	case PNFS_ATTEMPTED:
 		break;
 	case PNFS_TRY_AGAIN:
@@ -3019,6 +3020,7 @@ pnfs_do_read(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr)
 	switch (trypnfs) {
 	case PNFS_NOT_ATTEMPTED:
 		pnfs_read_through_mds(desc, hdr);
+		break;
 	case PNFS_ATTEMPTED:
 		break;
 	case PNFS_TRY_AGAIN: