Fix ext2fs_swap_inode_full() for in-inode xattrs on big-endian machines

Fix ext2fs_swap_inode_full() for in-inode xattrs on big-endian machines

After the fix for resize2fs's inode mover losing in-inode
extended attributes, the regression test I wrote caught
that the attrs were still getting lost on powerpc.

Looks like the problem is that ext2fs_swap_inode_full()
isn't paying attention to whether or not the EA magic is
in hostorder, so it's not recognized (and not swapped)
on BE machines.  Patch below seems to fix it.

Yay for regression tests.  ;)

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>