f2fs: fix to reset i_gc_failures correctly

Let's reset i_gc_failures to zero when we unset pinned state for file.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/file.c

@@ -2810,7 +2810,7 @@ static int f2fs_ioc_set_pin_file(struct file *filp, unsigned long arg)
 
 	if (!pin) {
 		clear_inode_flag(inode, FI_PIN_FILE);
-		F2FS_I(inode)->i_gc_failures[GC_FAILURE_PIN] = 1;
+		f2fs_i_gc_failures_write(inode, 0);
 		goto done;
 	}