[CMake] Removed user-setable option OGS_USE_MPI.

CMakeLists.txt

@@ -78,9 +78,6 @@ option(OGS_USE_LIS "Use Lis" OFF)
 # Parallel computing: vector and matrix algebraic caculation, solvers
 option(OGS_USE_PETSC "Use PETSc routines" OFF)
 
-# Paralleization
-option(OGS_USE_MPI "Use MPI" OFF)
-
 # Eigen
 option(OGS_USE_EIGEN "Use Eigen linear solver" ON)
 option(OGS_USE_EIGEN_UNSUPPORTED "Use Eigen unsupported modules" ON)

Tests/CMakeLists.txt

@@ -28,7 +28,7 @@ if(OGS_BUILD_SWMM)
     APPEND_SOURCE_FILES(TEST_SOURCES FileIO_SWMM)
 endif()
 
-if(OGS_USE_PETSC OR OGS_USE_MPI)
+if(OGS_USE_PETSC)
     list(REMOVE_ITEM TEST_SOURCES NumLib/TestSerialLinearSolver.cpp)
 endif()