clean shmem_file_setup() a bit

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

mm/shmem.c

@@ -2873,15 +2873,14 @@ EXPORT_SYMBOL_GPL(shmem_truncate_range);
  */
 struct file *shmem_file_setup(const char *name, loff_t size, unsigned long flags)
 {
-	int error;
-	struct file *file;
+	struct file *res;
 	struct inode *inode;
 	struct path path;
 	struct dentry *root;
 	struct qstr this;
 
 	if (IS_ERR(shm_mnt))
-		return (void *)shm_mnt;
+		return ERR_CAST(shm_mnt);
 
 	if (size < 0 || size > MAX_LFS_FILESIZE)
 		return ERR_PTR(-EINVAL);
@@ -2889,7 +2888,7 @@ struct file *shmem_file_setup(const char *name, loff_t size, unsigned long flags
 	if (shmem_acct_size(flags, size))
 		return ERR_PTR(-ENOMEM);
 
-	error = -ENOMEM;
+	res = ERR_PTR(-ENOMEM);
 	this.name = name;
 	this.len = strlen(name);
 	this.hash = 0; /* will go */
@@ -2899,7 +2898,7 @@ struct file *shmem_file_setup(const char *name, loff_t size, unsigned long flags
 		goto put_memory;
 	path.mnt = mntget(shm_mnt);
 
-	error = -ENOSPC;
+	res = ERR_PTR(-ENOSPC);
 	inode = shmem_get_inode(root->d_sb, NULL, S_IFREG | S_IRWXUGO, 0, flags);
 	if (!inode)
 		goto put_dentry;
@@ -2909,23 +2908,23 @@ struct file *shmem_file_setup(const char *name, loff_t size, unsigned long flags
 	clear_nlink(inode);	/* It is unlinked */
 #ifndef CONFIG_MMU
 	error = ramfs_nommu_expand_for_mapping(inode, size);
+	res = ERR_PTR(error);
 	if (error)
 		goto put_dentry;
 #endif
 
-	file = alloc_file(&path, FMODE_WRITE | FMODE_READ,
+	res = alloc_file(&path, FMODE_WRITE | FMODE_READ,
 		  &shmem_file_operations);
-	error = PTR_ERR(file);
-	if (IS_ERR(file))
+	if (IS_ERR(res))
 		goto put_dentry;
 
-	return file;
+	return res;
 
 put_dentry:
 	path_put(&path);
 put_memory:
 	shmem_unacct_size(flags, size);
-	return ERR_PTR(error);
+	return res;
 }
 EXPORT_SYMBOL_GPL(shmem_file_setup);