Copy i_flags to jfs inode flags on write

This mirrors Jan Kara's patches for ext3.  This patch makes sure that
changes made to inode->i_flags are reflected on disk for jfs.  It also
moves a call of jfs_set_inode_flags() to be more consistent with where
jfs_get_inode_flags() is called.

Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>