target-alpha: fix syscall error check

(re-add commit 5689)

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5692 c046a42c-6fe2-441c-8c8c-71466251a162
diff --git a/hw/alpha_palcode.c b/hw/alpha_palcode.c
index 38466db..351bb48 100644
--- a/hw/alpha_palcode.c
+++ b/hw/alpha_palcode.c
@@ -1059,7 +1059,7 @@
 
 void call_pal (CPUState *env, int palcode)
 {
-    target_ulong ret;
+    target_long ret;
 
     if (logfile != NULL)
         fprintf(logfile, "%s: palcode %02x\n", __func__, palcode);