target/riscv: fix return value of do_opivx_widen()

do_opivx_widen() should return false if check function returns false.

Signed-off-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20200710104920.13550-4-frank.chang@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

target/riscv/insn_trans/trans_rvv.inc.c

@@ -1151,7 +1151,7 @@ static bool do_opivx_widen(DisasContext *s, arg_rmrr *a,
     if (opivx_widen_check(s, a)) {
         return opivx_trans(a->rd, a->rs1, a->rs2, a->vm, fn, s);
     }
-    return true;
+    return false;
 }
 
 #define GEN_OPIVX_WIDEN_TRANS(NAME) \