Remove some warnings about:
   Boolean result is used in bitwise operation
   Suspicious condition (assignment + comparison)

Also reduce scope of a variable.

Change-Id: I553e5a09ed1d6276be61efbbb2c28d165a69af39
Signed-off-by: jailletc36 <christophe.jaillet@wanadoo.fr>
Reviewed-on: https://gerrit.libreoffice.org/1031Reviewed-by: Tor Lillqvist <tml@iki.fi>
Tested-by: Tor Lillqvist <tml@iki.fi>