Kernel: Access OpenFileDescriptions::max_open() statically in Syscalls

Author: https://github.com/Hendiadyoin1
Commit: f38d32535c
Pull-request: https://github.com/SerenityOS/serenity/pull/11294

Kernel/Syscalls/pipe.cpp

@@ -13,7 +13,7 @@ ErrorOr<FlatPtr> Process::sys$pipe(int pipefd[2], int flags)
 {
     VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
     REQUIRE_PROMISE(stdio);
-    if (fds().open_count() + 2 > fds().max_open())
+    if (fds().open_count() + 2 > OpenFileDescriptions::max_open())
         return EMFILE;
     // Reject flags other than O_CLOEXEC, O_NONBLOCK
     if ((flags & (O_CLOEXEC | O_NONBLOCK)) != flags)