RFR: 8346231: RISC-V: Fix incorrect assertion in SharedRuntime::generate_handler_blob

[Fei Yang]

Hi, please review this small change fixing several typos in assertion code.

I find that the verification of encoding of the poll instruction in this blob is not correct.
The code loads the instruction and checks for three bit fields, but it uses wrong masks. This
won't trigger an assertion failure as the masks used are the same as the expected values.

Testing on linux-riscv64 platform:
- [ ] hotspot:tier1 (fastdebug)

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Commit messages:
 - 8346231: RISC-V: Fix incorrect assertion in SharedRuntime::generate_handler_blob

Changes: https://git.openjdk.org/jdk/pull/22750/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22750&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8346231
  Stats: 4 lines in 1 file changed: 1 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/22750.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22750/head:pull/22750

PR: https://git.openjdk.org/jdk/pull/22750