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>

arch/x86/kernel/entry_32.S

@@ -456,7 +456,7 @@ sysenter_audit:
 	movl %ebx,%ecx			/* 3rd arg: 1st syscall arg */
 	movl %eax,%edx			/* 2nd arg: syscall number */
 	movl $AUDIT_ARCH_I386,%eax	/* 1st arg: audit arch */
-	call audit_syscall_entry
+	call __audit_syscall_entry
 	pushl_cfi %ebx
 	movl PT_EAX(%esp),%eax		/* reload syscall number */
 	jmp sysenter_do_call

arch/x86/kernel/entry_64.S

@@ -549,7 +549,7 @@ badsys:
 #ifdef CONFIG_AUDITSYSCALL
 	/*
 	 * Fast path for syscall audit without full syscall trace.
-	 * We just call audit_syscall_entry() directly, and then
+	 * We just call __audit_syscall_entry() directly, and then
 	 * jump back to the normal fast path.
 	 */
 auditsys:
@@ -559,7 +559,7 @@ auditsys:
 	movq %rdi,%rdx			/* 3rd arg: 1st syscall arg */
 	movq %rax,%rsi			/* 2nd arg: syscall number */
 	movl $AUDIT_ARCH_X86_64,%edi	/* 1st arg: audit arch */
-	call audit_syscall_entry
+	call __audit_syscall_entry
 	LOAD_ARGS 0		/* reload call-clobbered registers */
 	jmp system_call_fastpath
 

arch/x86/kernel/ptrace.c

@@ -1392,20 +1392,18 @@ long syscall_trace_enter(struct pt_regs *regs)
 	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 		trace_sys_enter(regs, regs->orig_ax);
 
-	if (unlikely(current->audit_context)) {
-		if (IS_IA32)
-			audit_syscall_entry(AUDIT_ARCH_I386,
-					    regs->orig_ax,
-					    regs->bx, regs->cx,
-					    regs->dx, regs->si);
+	if (IS_IA32)
+		audit_syscall_entry(AUDIT_ARCH_I386,
+				    regs->orig_ax,
+				    regs->bx, regs->cx,
+				    regs->dx, regs->si);
 #ifdef CONFIG_X86_64
-		else
-			audit_syscall_entry(AUDIT_ARCH_X86_64,
-					    regs->orig_ax,
-					    regs->di, regs->si,
-					    regs->dx, regs->r10);
+	else
+		audit_syscall_entry(AUDIT_ARCH_X86_64,
+				    regs->orig_ax,
+				    regs->di, regs->si,
+				    regs->dx, regs->r10);
 #endif
-	}
 
 	return ret ?: regs->orig_ax;
 }