Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2016-04-29' into staging

QAPI patches for 2016-04-29

# gpg: Signature made Fri 29 Apr 2016 10:13:08 BST using RSA key ID EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>"

* remotes/armbru/tags/pull-qapi-2016-04-29:
  qapi: Don't pass NULL to printf in string input visitor
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

qapi/string-input-visitor.c

@@ -222,7 +222,7 @@ static void parse_type_int64(Visitor *v, const char *name, int64_t *obj,
     return;
 
 error:
-    error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name,
+    error_setg(errp, QERR_INVALID_PARAMETER_VALUE, name ? name : "null",
                "an int64 value or range");
 }