fix -Wabsolute-value compiler warning

fixes:
Clock.c:2011:14: warning: using integer absolute value function ‘abs’ when argument is of floating-point type ‘float’ [-Wabsolute-value]
 2011 |             (abs(new->clock.update) <= SECOND_HAND_TIME);
      |              ^~~

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
6 jobs for ThomasKuehne/xclock-compiler_warnings in 1 minute and 11 seconds