fixup! Initial integration of FdLock into System::FileDescriptor and System::Socket

Author: ysbaddaden

src/crystal/system/unix/file_descriptor.cr

@@ -61,7 +61,7 @@ module Crystal::System::FileDescriptor
   end
 
   private def system_close_on_exec?
-    flags = FileDescriptor.fcntl(LibC::F_GETFD)
+    flags = FileDescriptor.fcntl(fd, LibC::F_GETFD)
     flags.bits_set? LibC::FD_CLOEXEC
   end
 

src/crystal/system/unix/socket.cr

@@ -1,6 +1,7 @@
 require "c/netdb"
 require "c/netinet/tcp"
 require "c/sys/socket"
+require "crystal/fd_lock"
 
 module Crystal::System::Socket
   {% if IO.has_constant?(:Evented) %}