kernel, manager: Track upstream changes (#195)

* These commits are carefully picked from upstream (tiann/KernelSU)

- Picked range:
8c5f485f27..e5f43a3427

Signed-off-by: Faris <rissu.ntk@gmail.com>
Co-authored-by: Wang Han <416810799@qq.com>
Co-authored-by: TwinbornPlate75 <3342733415@qq.com>
Co-authored-by: KOWX712 <leecc0503@gmail.com>
Co-authored-by: Ylarod <me@ylarod.cn>
Co-authored-by: YuKongA <70465933+YuKongA@users.noreply.github.com>
Co-authored-by: backslashxx <118538522+backslashxx@users.noreply.github.com>
Co-authored-by: 5ec1cff <56485584+5ec1cff@users.noreply.github.com>
Co-authored-by: weishu <twsxtd@gmail.com>

kernel/selinux/selinux_defs.h

@@ -33,4 +33,10 @@
 #define __setenforce(val)
 #endif
 
+#ifdef KSU_OPTIONAL_SELINUX_CRED
+#define __selinux_cred(cred) (selinux_cred(cred))
+#else
+#define __selinux_cred(cred) (cred->security)
+#endif
+
 #endif