s390x: Fix stoc direction

The store conditional instruction wants to store when the condition
is fulfilled, so we should branch out when it's not true.

The code today branches out when the condition is true, clearly
reversing the logic. Fix it up by negating the condition.

Signed-off-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Richard Henderson <rth@twiddle.net>

target-s390x/translate.c

@@ -3082,6 +3082,10 @@ static ExitStatus op_soc(DisasContext *s, DisasOps *o)
 
     disas_jcc(s, &c, get_field(s->fields, m3));
 
+    /* We want to store when the condition is fulfilled, so branch
+       out when it's not */
+    c.cond = tcg_invert_cond(c.cond);
+
     lab = gen_new_label();
     if (c.is_64) {
         tcg_gen_brcond_i64(c.cond, c.u.s64.a, c.u.s64.b, lab);