Summary:
Currently, the RPM package will install the lib and header files into `/usr/package/lib` and `/usr/package/include` which is not in the default search paths. It is reasonable to install them under `/usr/lib` and `/usr/include` so that no extra configuration is required.
Closes https://github.com/facebook/rocksdb/pull/2221
Differential Revision: D5054030
Pulled By: yiwu-arbug
fbshipit-source-id: 1d23de5ff21f07e6738c9dfa04429acd7a839143