virtio-input: add parenthesis to const_le{16, 32}

"_x" must be "(_x)" otherwise things fail if you pass in expressions.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Message-id: 1460440299-26654-1-git-send-email-kraxel@redhat.com

include/hw/virtio/virtio-input.h

@@ -15,13 +15,13 @@ typedef struct virtio_input_event virtio_input_event;
 
 #if defined(HOST_WORDS_BIGENDIAN)
 # define const_le32(_x)                          \
-    (((_x & 0x000000ffU) << 24) |                \
-     ((_x & 0x0000ff00U) <<  8) |                \
-     ((_x & 0x00ff0000U) >>  8) |                \
-     ((_x & 0xff000000U) >> 24))
+    ((((_x) & 0x000000ffU) << 24) |              \
+     (((_x) & 0x0000ff00U) <<  8) |              \
+     (((_x) & 0x00ff0000U) >>  8) |              \
+     (((_x) & 0xff000000U) >> 24))
 # define const_le16(_x)                          \
-    (((_x & 0x00ff) << 8) |                      \
-     ((_x & 0xff00) >> 8))
+    ((((_x) & 0x00ff) << 8) |                    \
+     (((_x) & 0xff00) >> 8))
 #else
 # define const_le32(_x) (_x)
 # define const_le16(_x) (_x)