fix errors in detecting non-modified areas

function                                             old     new   delta
screen_char                                          100     102      +2
cleanup                                               84      86      +2
screen_dump                                          215     210      -5
conspy_main                                         1503    1491     -12

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
1 file changed