f2fs: fix to show missing bits in FS_IOC_GETFLAGS

This patch fixes to show missing encrypt/inline_data flag in
FS_IOC_GETFLAGS like ext4 does.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>