[RISCV] Fix typo in ImmPlus1 SDNodeXForm (#190785)
getValuePtrVTpe -> getValueType. Currently dead code since GlobalISel
uses a custom renderer instead of the SDNodeXForm body, but should be
correct in case the SDAG path ever picks up these patterns.
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
