do_lwsync_fixups doesn't work on 64bit, we end up writing lwsyncs to the
wrong addresses:
0:mon> di c0000001000bfacc
c0000001000bfacc 7c2004ac lwsync
Since the lwsync section has negative offsets we need to use a signed int
pointer so we sign extend the value.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>