[RISCV][NFC] Remove dead CHECK lines from vararg.ll test

The RISCV32 check prefix is no longer used so these lines are dead.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@343757 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed