RFR: RISC-V: Fix typo in InterpreterMacroAssembler::call_VM_preemptable

[Fei Yang]

Seems to me that there exists two typos in loom commit https://github.com/openjdk/loom/commit/0b14b49e2ba05a62268dc02f1cfe1e258173deb7 (define call_VM_preemptable for interpreter). @pchilano : Could you please confirm that? Thanks.

Testing performed on linux-riscv64:
- [x] make test TEST="hotspot_loom jdk_loom" (release build)
- [x] make test TEST="hotspot_loom jdk_loom" TEST_VM_OPTS="-XX:+VerifyStack" (fastdebug build)

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Commit messages:
 - RISC-V: Fix typo in InterpreterMacroAssembler::call_VM_preemptable

Changes: https://git.openjdk.org/loom/pull/213/files
  Webrev: https://webrevs.openjdk.org/?repo=loom&pr=213&range=00
  Stats: 2 lines in 2 files changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/loom/pull/213.diff
  Fetch: git fetch https://git.openjdk.org/loom.git pull/213/head:pull/213

PR: https://git.openjdk.org/loom/pull/213