Fix integer overflow for fence_timeout (#152)
Fix integer overflow for fence_timeout (#152)

The fence_timeout (in milliseconds) is stored as a uint32_t and is
later converted to nanoseconds (as required by vkWaitForFences), which
requires more than 32 bits for any timeout larger than ~4.3 seconds.
google/amber,google/amber,google/amber,google/amber,google/amber