8356188: RISC-V: Cleanup effect of vmaskcmp_fp

Reviewed-by: fyang, gcao

Author: DingliZhang

src/hotspot/cpu/riscv/riscv_v.ad

@@ -251,7 +251,6 @@ instruct vmaskcmp_fp(vRegMask dst, vReg src1, vReg src2, immI cond) %{
   predicate(Matcher::vector_element_basic_type(n) == T_FLOAT ||
             Matcher::vector_element_basic_type(n) == T_DOUBLE);
   match(Set dst (VectorMaskCmp (Binary src1 src2) cond));
-  effect(TEMP_DEF dst);
   format %{ "vmaskcmp_fp $dst, $src1, $src2, $cond" %}
   ins_encode %{
     BasicType bt = Matcher::vector_element_basic_type(this);