Need to use MPI_CXX_INCLUDE_PATH instead of MPI_C_INCLUDE_PATH on Fedora 28 with cmake 3.11

cmake/CMakeLists.txt

@@ -66,7 +66,7 @@ find_package(MPI QUIET)
 option(BUILD_MPI "Build MPI version" ${MPI_FOUND})
 if(BUILD_MPI)
   find_package(MPI REQUIRED)
-  include_directories(${MPI_C_INCLUDE_PATH})
+  include_directories(${MPI_CXX_INCLUDE_PATH})
   list(APPEND LAMMPS_LINK_LIBS ${MPI_CXX_LIBRARIES})
   option(LAMMPS_LONGLONG_TO_LONG "Workaround if your system or MPI version does not recognize 'long long' data types" OFF)
   if(LAMMPS_LONGLONG_TO_LONG)
@@ -833,7 +833,7 @@ else()
 endif()
 message(STATUS "Link libraries: ${LAMMPS_LINK_LIBS}")
 if(BUILD_MPI)
-  message(STATUS "Using mpi with headers in ${MPI_C_INCLUDE_PATH} and ${MPI_CXX_LIBRARIES}")
+  message(STATUS "Using mpi with headers in ${MPI_CXX_INCLUDE_PATH} and ${MPI_CXX_LIBRARIES}")
 endif()
 if(ENABLED_GPU)
   message(STATUS "GPU Api: ${GPU_API}")