[llvm] [RISCV][NFC] consolidate simple conditional statements (PR #70423)

[Ben Shi via llvm-commits]

benshi001 wrote:

1. Add who contribute to RISCV recently as your reviewers.
2. Change your commit message to `[RISCV][NFC] Combine redundant `if` statements`

https://github.com/llvm/llvm-project/pull/70423