Fix build : change MYSQL_ADD_PLUGIN to be MACRO again, rather than FUNCTION

cmake/plugin.cmake

@@ -28,15 +28,13 @@ INCLUDE(${MYSQL_CMAKE_SCRIPT_DIR}/cmake_parse_arguments.cmake)
 # [LINK_LIBRARIES lib1...libN]
 # [DEPENDENCIES target1...targetN]
 
-FUNCTION(MYSQL_ADD_PLUGIN)
+MACRO(MYSQL_ADD_PLUGIN)
   MYSQL_PARSE_ARGUMENTS(ARG
     "LINK_LIBRARIES;DEPENDENCIES;MODULE_OUTPUT_NAME;STATIC_OUTPUT_NAME;COMPONENT;CONFIG"
     "STORAGE_ENGINE;STATIC_ONLY;MODULE_ONLY;MANDATORY;DEFAULT;DISABLED;RECOMPILE_FOR_EMBEDDED;CLIENT"
     ${ARGN}
   )
-  IF(WITHOUT_SERVER AND NOT ARG_CLIENT)
-    RETURN()
-  ENDIF()
+  IF(NOT WITHOUT_SERVER OR ARG_CLIENT)
 
   # Add common include directories
   INCLUDE_DIRECTORIES(${CMAKE_SOURCE_DIR}/include 
@@ -238,7 +236,9 @@ FUNCTION(MYSQL_ADD_PLUGIN)
   IF(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/mysql-test")
     INSTALL_MYSQL_TEST("${CMAKE_CURRENT_SOURCE_DIR}/mysql-test/" "plugin/${subpath}")
   ENDIF()
-ENDFUNCTION()
+
+  ENDIF(NOT WITHOUT_SERVER OR ARG_CLIENT)
+ENDMACRO()
 
 
 # Add all CMake projects under storage  and plugin