RR graph edge creation uses a incorrect switch type for decremental tracks

[saaramahmoudi]

Description

While creating RR edge, incremental and decremental tracks use the same seg_details of inc_track. Although this is incorrect, it doesn't affect the quality of results because we don't have an architecture that uses different muxes for incremental and decremental tracks. So, I don't expect anything to change by this fix.

Types of changes

• [x] Bug fix (change which fixes an issue)
• [ ] New feature (change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

[vaughnbetz]

Thanks Sara. Will merge once CI is green, although as you say this looks quite safe.