SuperBuild: pipe build logs to file (libsvm)

SuperBuild/CMake/External_libsvm.cmake

@@ -35,6 +35,9 @@ ExternalProject_Add(LIBSVM
   PATCH_COMMAND ${CMAKE_COMMAND} -E copy
   ${CMAKE_SOURCE_DIR}/patches/LIBSVM/CMakeLists.txt
   ${LIBSVM_SB_SRC}
+  LOG_CONFIGURE 1
+  LOG_BUILD 1
+  LOG_INSTALL 1
   )
 
 set(_SB_LIBSVM_INCLUDE_DIR ${SB_INSTALL_PREFIX}/include)