Fix falcon constant time check in Valgrind

[cothan]

This PR fix Falcon constant time check in Valgrind.
I review the Valgrind output and Falcon inline comments. It appears that a new line has been introduced, rendering the constant time check invalid. Consequently, adjusting the line location by 1 resolves the issue. To enhance clarity, I have separated the checks for Generic and AVX2. Additionally, I have eliminated some redundant checks for a more streamlined code.

Fixes #1617.

• Does this PR change the input/output behaviour of a cryptographic algorithm (i.e., does it change known answer test values)? (If so, a version bump will be required from x.y.z to x.(y+1).0.)
• Does this PR change the list of algorithms available -- either adding, removing, or renaming? Does this PR otherwise change an API? (If so, PRs in fully supported downstream projects dependent on these, i.e., oqs-provider and OQS-OpenSSH will also need to be ready for review and merge by the time this is merged.)

[dstebila]

I'll run locally and let you know the results when they're done.

FYI it's possible to run Github actions locally. Install act and then you can run Github actions workflows in Docker containers; e.g., act --job constant-time-x64

[SWilson4]

I've run the tests locally; the Falcon tests pass now. Thanks very much!

[dstebila]

I'll run locally and let you know the results when they're done.

FYI it's possible to run Github actions locally. Install act and then you can run Github actions workflows in Docker containers; e.g., act --job constant-time-x64

They pass for me.