[RISCV] Fix Zvfbfa tests from #171794 to mitigate UTC bug. NFCI (#173125)
Context:
https://github.com/llvm/llvm-project/pull/171794#discussion_r2614489484
For some reasons, UTC is unable to merge the 'ZVFHMIN' and 'ZVFBFA'
CHECK lines in some of the test functions, and emits incorrect CHECK
lines for them, once you run UTC again on the file.
This hinders the ability to update these tests in bulk, as one has to
manually remove the excessed ZVFBFA lines. While I don't know how to fix
UTC at this moment, I found a workaround that simply re-orders these two
check prefixes.
This is effectively a NFC