f2fs: fix writecount false positive in releasing compress blocks

In current condition check, if it detects writecount, it return -EBUSY
regardless of f_mode of the file. Fixed it.
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/file.c

@@ -3511,7 +3511,8 @@ static int f2fs_release_compress_blocks(struct file *filp, unsigned long arg)
 	inode_lock(inode);
 
 	writecount = atomic_read(&inode->i_writecount);
-	if ((filp->f_mode & FMODE_WRITE && writecount != 1) || writecount) {
+	if ((filp->f_mode & FMODE_WRITE && writecount != 1) ||
+			(!(filp->f_mode & FMODE_WRITE) && writecount)) {
 		ret = -EBUSY;
 		goto out;
 	}