small refactoring o innobase/CMakeLists.txt

allow to build with -DPLUGIN_INNOBASE=NO

storage/innobase/CMakeLists.txt

@@ -150,14 +150,7 @@ SET(INNOBASE_SOURCES
 	ut/ut0wqueue.cc
 	ut/ut0timer.cc)
 
-IF(WITH_INNODB)
-  # Legacy option
-  SET(WITH_INNOBASE_STORAGE_ENGINE TRUE)
-ENDIF()
-
 MYSQL_ADD_PLUGIN(innobase ${INNOBASE_SOURCES} STORAGE_ENGINE
-#  MODULE_ONLY
-#  MODULE_OUTPUT_NAME ha_innodb
   DEFAULT RECOMPILE_FOR_EMBEDDED
   LINK_LIBRARIES
 	${ZLIB_LIBRARY}
@@ -166,8 +159,8 @@ MYSQL_ADD_PLUGIN(innobase ${INNOBASE_SOURCES} STORAGE_ENGINE
 	${LIBSYSTEMD}
 	${LINKER_SCRIPT})
 
-IF(WITH_INNOBASE_STORAGE_ENGINE)
-  ADD_DEPENDENCIES(innobase GenError)
+IF(NOT TARGET innobase)
+  RETURN()
 ENDIF()
 
 # A GCC bug causes crash when compiling these files on ARM64 with -O1+