The big NULL replacement party part 1.

This is meant to be a safer alternative since
NULL can often be 0. Let's not rely on that.

And yes, I know this is a lot of files. This is
a safer thing to do in big commits vs for loops.

src/archutils/Win32/GetFileInformation.cpp

@@ -144,7 +144,7 @@ bool GetProcessFileName( uint32_t iProcessID, RString &sName )
 			}
 		}
 
-		if( pGetProcessImageFileName != NULL )
+		if( pGetProcessImageFileName != nullptr )
 		{
 			HANDLE hProc = OpenProcess( PROCESS_VM_READ|PROCESS_QUERY_INFORMATION, NULL, iProcessID );
 			if( hProc == NULL )