9p: Add missing cast for the error return value in v9fs_get_inode

Cast the error return value (ENOMEM) in v9fs_get_inode() to its
correct type using ERR_PTR.
Signed-off-by: NAbhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

fs/9p/vfs_inode.c

@@ -215,7 +215,7 @@ struct inode *v9fs_get_inode(struct super_block *sb, int mode)
 	inode = new_inode(sb);
 	if (!inode) {
 		P9_EPRINTK(KERN_WARNING, "Problem allocating inode\n");
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 	}
 
 	inode->i_mode = mode;