PPC: fix segfault in signal handling code

Removed h2g() macro around the ka->_sa_handler due to the _sa_handler being a
guest memory address.

Changed the __put_user to put_user as it was attempting to put a value at the
stack address but the new address is a guest memory address, __put_user is
for host memory addresses.

Signed-off-by: Samuel Seay <LightningTH@GMail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[agraf: change subject line, reformat commit message]
Signed-off-by: Alexander Graf <agraf@suse.de>

linux-user/signal.c

@@ -4584,7 +4584,7 @@ static void setup_frame(int sig, struct target_sigaction *ka,
 
     signal = current_exec_domain_sig(sig);
 
-    err |= __put_user(h2g(ka->_sa_handler), &sc->handler);
+    err |= __put_user(ka->_sa_handler, &sc->handler);
     err |= __put_user(set->sig[0], &sc->oldmask);
 #if defined(TARGET_PPC64)
     err |= __put_user(set->sig[0] >> 32, &sc->_unused[3]);
@@ -4606,7 +4606,7 @@ static void setup_frame(int sig, struct target_sigaction *ka,
 
     /* Create a stack frame for the caller of the handler.  */
     newsp = frame_addr - SIGNAL_FRAMESIZE;
-    err |= __put_user(env->gpr[1], (target_ulong *)(uintptr_t) newsp);
+    err |= put_user(env->gpr[1], newsp, target_ulong);
 
     if (err)
         goto sigsegv;