Update the variable checked by the loop condition (expDiff).
Backport the update from Previous.
Fixes: 591596b77a ("target/m68k: add fmod/frem")
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20180508203937.16796-1-laurent@vivier.eu>