qapi: Use qemu_strtod_finite() in qobject-input-visitor

Let's use the new function. Just as current behavior, we have to
consume the whole string (now it's just way clearer what's going on).
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Message-Id: <20181121164421.20780-5-david@redhat.com>
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>

qapi/qobject-input-visitor.c

@@ -562,19 +562,20 @@ static void qobject_input_type_number_keyval(Visitor *v, const char *name,
 {
     QObjectInputVisitor *qiv = to_qiv(v);
     const char *str = qobject_input_get_keyval(qiv, name, errp);
-    char *endp;
+    double val;
 
     if (!str) {
         return;
     }
 
-    errno = 0;
-    *obj = strtod(str, &endp);
-    if (errno || endp == str || *endp || !isfinite(*obj)) {
+    if (qemu_strtod_finite(str, NULL, &val)) {
         /* TODO report -ERANGE more nicely */
         error_setg(errp, QERR_INVALID_PARAMETER_TYPE,
                    full_name(qiv, name), "number");
+        return;
     }
+
+    *obj = val;
 }
 
 static void qobject_input_type_any(Visitor *v, const char *name, QObject **obj,