Post-merge fix: Rdb_io_watchdog doesn't support windows

Part #2.

storage/rocksdb/CMakeLists.txt

@@ -126,7 +126,7 @@ endif()
 
 INCLUDE(build_rocksdb.cmake)
 
-set(rocksdb_aux_lib_sources
+ADD_CONVENIENCE_LIBRARY(rocksdb_aux_lib
   ha_rocksdb_proto.h
   logger.h
   rdb_comparator.h
@@ -143,16 +143,6 @@ set(rocksdb_aux_lib_sources
   rdb_mariadb_port.h
 )
 
-if(WIN32)
-else()
-  list(APPEND rocksdb_aux_lib_sources
-    rdb_io_watchdog.cc
-    rdb_io_watchdog.h
-  )
-endif()
-
-ADD_CONVENIENCE_LIBRARY(rocksdb_aux_lib ${rocksdb_aux_lib_sources})
-
 ADD_DEPENDENCIES(rocksdb_aux_lib GenError)
 
 # MARIAROCKS-TODO: how to properly depend on -lrt ?

storage/rocksdb/rdb_io_watchdog.cc

@@ -21,6 +21,8 @@
 #include <string>
 #include <vector>
 
+#ifndef _WIN32
+
 namespace myrocks {
 
 void Rdb_io_watchdog::expire_io_callback(union sigval timer_data) {
@@ -231,3 +233,6 @@ int Rdb_io_watchdog::reset_timeout(const uint32_t &write_timeout) {
 }
 
 }  // namespace myrocks
+
+#endif
+