fix a bug in FindGlog.cmake
fix a bug in FindGlog.cmake

Summary:
Call `find_package_handle_standard_args()` with a package name of `Glog`
rather than `glog`, so that it sets `Glog_FOUND` rather than `glog_FOUND`.
This argument needs to match the case of our file name (FindGlog.cmake), since
CMake variables are case-sensitive.

Reviewed By: Orvid

Differential Revision: D36678745

fbshipit-source-id: 6a0578103d12684e414664b17f7880664c0141f4

facebook/watchman,facebook/watchman,facebook/watchman,facebook/watchman,facebook/watchman,facebook/watchman,facebook/watchman,facebook/watchman,facebook/watchman