coda: deal correctly with allocation failure from coda_cnode_makectl()

lookup should fail with ENOMEM, not silently make dentry negative.
Switched to saner calling conventions, while we are at it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/coda/coda_fs_i.h b/fs/coda/coda_fs_i.h
index e35071b..1c17446f 100644
--- a/fs/coda/coda_fs_i.h
+++ b/fs/coda/coda_fs_i.h
@@ -51,7 +51,7 @@
 
 int coda_cnode_make(struct inode **, struct CodaFid *, struct super_block *);
 struct inode *coda_iget(struct super_block *sb, struct CodaFid *fid, struct coda_vattr *attr);
-int coda_cnode_makectl(struct inode **inode, struct super_block *sb);
+struct inode *coda_cnode_makectl(struct super_block *sb);
 struct inode *coda_fid_to_inode(struct CodaFid *fid, struct super_block *sb);
 void coda_replace_fid(struct inode *, struct CodaFid *, struct CodaFid *);