target/arm: Fix sqrt_f16 exception raising

We are meant to explicitly pass fpst, not cpu_env.

Cc: qemu-stable@nongnu.org
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Signed-off-by: NRichard Henderson <richard.henderson@linaro.org>
Tested-by: NAlex Bennée <alex.bennee@linaro.org>
Message-id: 20180512003217.9105-12-richard.henderson@linaro.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

target/arm/translate-a64.c

@@ -4976,7 +4976,8 @@ static void handle_fp_1src_half(DisasContext *s, int opcode, int rd, int rn)
         tcg_gen_xori_i32(tcg_res, tcg_op, 0x8000);
         break;
     case 0x3: /* FSQRT */
-        gen_helper_sqrt_f16(tcg_res, tcg_op, cpu_env);
+        fpst = get_fpstatus_ptr(true);
+        gen_helper_sqrt_f16(tcg_res, tcg_op, fpst);
         break;
     case 0x8: /* FRINTN */
     case 0x9: /* FRINTP */