[CI] address cmakelint warnings about whitespace (#9674)

CMakeLists.txt

@@ -102,8 +102,10 @@ if (JVM_BINDINGS AND R_LIB)
   message(SEND_ERROR "`R_LIB' is not compatible with `JVM_BINDINGS' as they both have customized configurations.")
 endif()
 if(R_LIB AND GOOGLE_TEST)
-  message(WARNING "Some C++ unittests will fail with `R_LIB` enabled,
- as R package redirects some functions to R runtime implementation.")
+  message(
+    WARNING
+    "Some C++ tests will fail with `R_LIB` enabled, as R package redirects some functions to R runtime implementation."
+  )
 endif()
 if(PLUGIN_RMM AND NOT (USE_CUDA))
   message(SEND_ERROR "`PLUGIN_RMM` must be enabled with `USE_CUDA` flag.")
@@ -228,8 +230,10 @@ add_subdirectory(${xgboost_SOURCE_DIR}/dmlc-core)
 
 if(MSVC)
   if(TARGET dmlc_unit_tests)
-    target_compile_options(dmlc_unit_tests PRIVATE
-                           -D_CRT_SECURE_NO_WARNINGS -D_CRT_SECURE_NO_DEPRECATE)
+    target_compile_options(
+        dmlc_unit_tests PRIVATE
+        -D_CRT_SECURE_NO_WARNINGS -D_CRT_SECURE_NO_DEPRECATE
+    )
   endif()
 endif()
 

cmake/Doc.cmake

@@ -8,7 +8,8 @@ function (run_doxygen)
   configure_file(
     ${xgboost_SOURCE_DIR}/doc/Doxyfile.in
     ${CMAKE_CURRENT_BINARY_DIR}/Doxyfile @ONLY)
-  add_custom_target( doc_doxygen ALL
+  add_custom_target(
+    doc_doxygen ALL
     COMMAND ${DOXYGEN_EXECUTABLE} ${CMAKE_CURRENT_BINARY_DIR}/Doxyfile
     WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
     COMMENT "Generate C APIs documentation."