Fix bug identified by Badari Pulavarty <pbadari@us.ibm.com>

Local variable `handle' will become stale if ext3_direct_io_get_blocks()
closes off the current transaction and starts a new one.  This causes a BUG in
journal_stop().

So reacquire the handle from *current after performing the I/O.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>