Scripts: WARN_MODE off by default

cmake/print_warnings.cmake

-IF(NOT DEFINED WARN_MODE)
-  IF(CMAKE_BUILD_TYPE MATCHES "Debug")
-    SET(WARN_MODE "late")
-  ELSE()
-    SET(WARN_MODE "early")
-  ENDIF()
-ENDIF()
-
-IF(NOT WARN_MODE STREQUAL "early" AND
+IF(DEFINED WARN_MODE)
+  IF(NOT WARN_MODE STREQUAL "early" AND
       NOT WARN_MODE STREQUAL "late" AND
       NOT WARN_MODE STREQUAL "both")
     MESSAGE(FATAL_ERROR "Unknown WARN_MODE: expected 'early', 'late' or 'both'")
-ENDIF()
+  ENDIF()
 
-SET_DIRECTORY_PROPERTIES(PROPERTIES RULE_LAUNCH_COMPILE
+  SET_DIRECTORY_PROPERTIES(PROPERTIES RULE_LAUNCH_COMPILE
     "bash ${CMAKE_SOURCE_DIR}/BUILD/capture_warnings.sh ${CMAKE_BINARY_DIR} ${WARN_MODE}")
-SET_DIRECTORY_PROPERTIES(PROPERTY ADDITIONAL_MAKE_CLEAN_FILES
+  SET_DIRECTORY_PROPERTIES(PROPERTY ADDITIONAL_MAKE_CLEAN_FILES
     "${CMAKE_BINARY_DIR}/compile.warnings")
-ADD_CUSTOM_TARGET(rm_compile.warnings ALL
+  ADD_CUSTOM_TARGET(rm_compile.warnings ALL
     COMMAND rm -f compile.warnings
     WORKING_DIRECTORY ${CMAKE_BINARY_DIR})
-ADD_CUSTOM_TARGET(print_warnings ALL
+  ADD_CUSTOM_TARGET(print_warnings ALL
     COMMAND bash -c '[ -f compile.warnings ] && { echo "Warnings found:" \; cat compile.warnings \; echo "" \; } \; true'
     DEPENDS mysqld rm_compile.warnings
     WORKING_DIRECTORY "${CMAKE_BINARY_DIR}")
 
-IF(TARGET explain_filename-t)
+  IF(TARGET explain_filename-t)
     ADD_DEPENDENCIES(print_warnings explain_filename-t)
-ENDIF()
+  ENDIF()
 
-IF(TARGET mysql_client_test)
+  IF(TARGET mysql_client_test)
     ADD_DEPENDENCIES(print_warnings mysql_client_test)
-ENDIF()
+  ENDIF()
 
-IF(TARGET udf_example)
+  IF(TARGET udf_example)
     ADD_DEPENDENCIES(print_warnings udf_example)
+  ENDIF()
 ENDIF()