Fix O_DIRECT in defined (#416)

There was a minor typo here. This fixes that

xref: #404 (comment)

Authors:
  - https://github.com/jakirkham

Approvers:
  - Mads R. B. Kristensen (https://github.com/madsbk)

URL: #416

cpp/include/kvikio/file_handle.hpp

@@ -71,7 +71,7 @@ inline int open_fd_parse_flags(const std::string& flags, bool o_direct)
   }
   file_flags |= O_CLOEXEC;
   if (o_direct) {
-#if defined(O_DIRECTT)
+#if defined(O_DIRECT)
     file_flags |= O_DIRECT;
 #else
     throw std::invalid_argument("'o_direct' flag unsupported on this platform");