report: Fix backwards printing for threads
Fixes reporting like:
total threads in shared programs: 1776 -> 1709 (-3.77%)
threads in affected programs: 134 -> 67 (-50.00%)
helped: 0
HURT: 67
HURT stats (abs) min: 1 max: 1 x̄: 1.00 x̃: 1
HURT stats (rel) min: 50.00% max: 50.00% x̄: 50.00% x̃: 50.00%
95% mean confidence interval for threads value: -1.00 -1.00
95% mean confidence interval for threads %-change: -50.00% -50.00%
Threads are helped.
Threads are very much not helped :)