Fixed unitialized variable in blowfish bench.
Fixed unitialized variable in blowfish bench.

- this caused the benchmark to crash when compiled for 32-bit.

OpenISA/riscv-sbt,OpenISA/riscv-sbt,OpenISA/riscv-sbt,OpenISA/riscv-sbt,OpenISA/riscv-sbt,OpenISA/riscv-sbt,OpenISA/riscv-sbt