audit: inline audit_syscall_entry to reduce burden on archs

Every arch calls:

if (unlikely(current->audit_context))
	audit_syscall_entry()

which requires knowledge about audit (the existance of audit_context) in
the arch code.  Just do it all in static inline in audit.h so that arch's
can remain blissfully ignorant.

Signed-off-by: Eric Paris <eparis@redhat.com>
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 09d31c1..5b43325 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -1724,22 +1724,20 @@
 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 		trace_sys_enter(regs, regs->gpr[0]);
 
-	if (unlikely(current->audit_context)) {
 #ifdef CONFIG_PPC64
-		if (!is_32bit_task())
-			audit_syscall_entry(AUDIT_ARCH_PPC64,
-					    regs->gpr[0],
-					    regs->gpr[3], regs->gpr[4],
-					    regs->gpr[5], regs->gpr[6]);
-		else
+	if (!is_32bit_task())
+		audit_syscall_entry(AUDIT_ARCH_PPC64,
+				    regs->gpr[0],
+				    regs->gpr[3], regs->gpr[4],
+				    regs->gpr[5], regs->gpr[6]);
+	else
 #endif
-			audit_syscall_entry(AUDIT_ARCH_PPC,
-					    regs->gpr[0],
-					    regs->gpr[3] & 0xffffffff,
-					    regs->gpr[4] & 0xffffffff,
-					    regs->gpr[5] & 0xffffffff,
-					    regs->gpr[6] & 0xffffffff);
-	}
+		audit_syscall_entry(AUDIT_ARCH_PPC,
+				    regs->gpr[0],
+				    regs->gpr[3] & 0xffffffff,
+				    regs->gpr[4] & 0xffffffff,
+				    regs->gpr[5] & 0xffffffff,
+				    regs->gpr[6] & 0xffffffff);
 
 	return ret ?: regs->gpr[0];
 }