f2fs-tools: fix to le32 type variable correctly

f2fs-tools: fix to le32 type variable correctly

Fix below incorrect use:
- compare cpu and le32 type variable:
if (get_sb(feature) & cpu_to_le32(F2FS_FEATURE_RO))
- compare le32 type vairable:
if (c.feature & cpu_to_le32(F2FS_FEATURE_EXTRA_ATTR))
- miss get_sb(feature)
(cpu_to_le32(F2FS_FEATURE_RO) ? 1 : 0)
- update le32 type variable
sb->feature |= cpu_to_le32(F2FS_FEATURE_ENCRYPT);

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