target-s390x: fix PSW value on dynamical exception from helpers

runtime_exception computes the psw.addr value using the actual exception
address and the instruction length computed by calling the get_ilen
function. However as explained above the get_ilen code, it returns the
actual instruction length, and not the ILC. Therefore there is no need to
multiply the value by 2.
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>
Signed-off-by: NAlexander Graf <agraf@suse.de>

target-s390x/misc_helper.c

@@ -61,7 +61,7 @@ void QEMU_NORETURN runtime_exception(CPUS390XState *env, int excp,
     /* Advance past the insn.  */
     t = cpu_ldub_code(env, env->psw.addr);
     env->int_pgm_ilen = t = get_ilen(t);
-    env->psw.addr += 2 * t;
+    env->psw.addr += t;
 
     cpu_loop_exit(cs);
 }