ANDROID: Incremental fs: fix magic compatibility again

It's still magic number issue which cannot be compatible with
arm-32 platform, although we try to fix it in Iae4f3877444
("ANDROID: Incremental fs: magic number compatible 32-bit"),
there is still incompatible scenario, such as: get_incfs_node(),
it will return NULL then kernel exception will be trigger because
of NULL pointer access. (inode_set() -> get_incfs_node(), then used
node->xxx directly)

We change magic number directly, otherwise, we must fix above issues one by one.

Bug: 159772865
Fixes: Iae4f3877444("ANDROID: Incremental fs: magic number compatible 32-bit")
Signed-off-by: Peng Zhou <Peng.Zhou@mediatek.com>
Signed-off-by: mtk81325 <peng.zhou@mediatek.com>
Change-Id: I71f279c1bb55ea296ab33a47644f30df4a9f60a6