Remove includes in .cpp files for things the corresponding .h file already included

src/validation.cpp

@@ -15,7 +15,6 @@
 #include <consensus/tx_verify.h>
 #include <consensus/validation.h>
 #include <cuckoocache.h>
-#include <fs.h>
 #include <hash.h>
 #include <init.h>
 #include <policy/fees.h>
@@ -39,10 +38,8 @@
 #include <utilmoneystr.h>
 #include <utilstrencodings.h>
 #include <validationinterface.h>
-#include <versionbits.h>
 #include <warnings.h>
 
-#include <atomic>
 #include <sstream>
 
 #include <boost/algorithm/string/replace.hpp>