kernel: migrate barriers to spec barriers and code style thing

overkill, but yeah, might as well move on to the real deal.

[ rsuntk: Rename original variable name ]
Signed-off-by: backslashxx <118538522+backslashxx@users.noreply.github.com>
Signed-off-by: rsuntk <rsuntk@yukiprjkt.my.id>

kernel/kernel_compat.h

@@ -7,6 +7,14 @@
 #include "ss/policydb.h"
 #include "linux/key.h"
 
+#if defined(CONFIG_X86)
+#define KCOMPAT_BARRIER() barrier_nospec()
+#elif defined(CONFIG_ARM) || defined(CONFIG_ARM64)
+#define KCOMPAT_BARRIER() isb() // arch/arm64/include/asm/barrier.h
+#else
+#define KCOMPAT_BARRIER() barrier() // well, compiler atleast.
+#endif
+
 /**
  * list_count_nodes - count the number of nodes in a list
  * @head: the head of the list