kernel: handle optional backport for selinux_inode

* For supporting kernel 4.19 with 5.10 bpf backports.

Co-authored-by: rsuntk <rsuntk@yukiprjkt.my.id>

kernel/throne_tracker.h

@@ -1,5 +1,5 @@
-#ifndef __KSU_H_UID_OBSERVER
-#define __KSU_H_UID_OBSERVER
+#ifndef __KSU_H_THRONE_TRACKER
+#define __KSU_H_THRONE_TRACKER
 
 void ksu_throne_tracker_init(void);