Correct debug control for linuxulator faccessat

The Linuxulator provides per-syscall debug control via the
compat.linux.debug sysctl.  There's generally a 1:1 mapping between
sysctl setting and syscall, but faccessat was controlled by the access
setting, perhaps due to copy-paste.

Sponsored by:	Turing Robotic Industries

sys/compat/linux/linux_file.c

@@ -554,7 +554,7 @@ linux_faccessat(struct thread *td, struct linux_faccessat_args *args)
 	LCONVPATHEXIST_AT(td, args->filename, &path, dfd);
 
 #ifdef DEBUG
-	if (ldebug(access))
+	if (ldebug(faccessat))
 		printf(ARGS(access, "%s, %d"), path, args->amode);
 #endif