nfsd: Fix fall-through warnings for Clang

In preparation to enable -Wimplicit-fallthrough for Clang, fix multiple
warnings by explicitly adding a couple of break 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: Chuck Lever <chuck.lever@oracle.com>

fs/nfsd/nfs4state.c

@@ -3139,6 +3139,7 @@ nfsd4_exchange_id(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 			goto out_nolock;
 		}
 		new->cl_mach_cred = true;
+		break;
 	case SP4_NONE:
 		break;
 	default:				/* checked by xdr code */

fs/nfsd/nfsctl.c

@@ -1166,6 +1166,7 @@ static struct inode *nfsd_get_inode(struct super_block *sb, umode_t mode)
 		inode->i_fop = &simple_dir_operations;
 		inode->i_op = &simple_dir_inode_operations;
 		inc_nlink(inode);
+		break;
 	default:
 		break;
 	}