(x86/Sparc/PPC)-user: fix cpu_copy

b55a37c981914aa8ecd21b9a2a2fb37f39b917c5 moved the call to cpu_reset
to user emulators. But cpu_copy also initializes a CPU structure, so add the
call also there.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

linux-user/syscall.c

@@ -3553,6 +3553,9 @@ static int do_fork(CPUState *env, unsigned int flags, abi_ulong newsp,
         new_stack = ts->stack;
         /* we create a new CPU instance. */
         new_env = cpu_copy(env);
+#if defined(TARGET_I386) || defined(TARGET_SPARC) || defined(TARGET_PPC)
+        cpu_reset(new_env);
+#endif
         /* Init regs that differ from the parent.  */
         cpu_clone_regs(new_env, newsp);
         new_env->opaque = ts;