f2fs: clean up ioctl interface naming

Romve redundant prefix 'f2fs_' in the middle of f2fs_ioc_f2fs_write_checkpoint().
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/file.c

@@ -2129,7 +2129,7 @@ static int f2fs_ioc_gc_range(struct file *filp, unsigned long arg)
 	return ret;
 }
 
-static int f2fs_ioc_f2fs_write_checkpoint(struct file *filp, unsigned long arg)
+static int f2fs_ioc_write_checkpoint(struct file *filp, unsigned long arg)
 {
 	struct inode *inode = file_inode(filp);
 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
@@ -2910,7 +2910,7 @@ long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 	case F2FS_IOC_GARBAGE_COLLECT_RANGE:
 		return f2fs_ioc_gc_range(filp, arg);
 	case F2FS_IOC_WRITE_CHECKPOINT:
-		return f2fs_ioc_f2fs_write_checkpoint(filp, arg);
+		return f2fs_ioc_write_checkpoint(filp, arg);
 	case F2FS_IOC_DEFRAGMENT:
 		return f2fs_ioc_defragment(filp, arg);
 	case F2FS_IOC_MOVE_RANGE: