used to be __SYSTM_H__ before bus.h rev 1.26

or alternatively drop the ifndef around the include?

Building a kernel with BUS_SPACE_DEBUG requires -Wno-format
as busop.c debug format strings aren't right.

Index: sys/arch/sparc64/include/bus.h
===================================================================
RCS file: /cvs/src/sys/arch/sparc64/include/bus.h,v
diff -u -p -U21 -r1.37 bus.h
--- sys/arch/sparc64/include/bus.h	24 Dec 2023 11:12:34 -0000	1.37
+++ sys/arch/sparc64/include/bus.h	22 Oct 2024 03:44:24 -0000
@@ -67,43 +67,43 @@
 #define _MACHINE_BUS_H_
 
 #include <sys/atomic.h>
 
 #ifdef _KERNEL
 
 /*
  * Debug hooks
  */
 
 #define	BSDB_ACCESS	0x01
 #define BSDB_MAP	0x02
 #define BSDB_ASSERT	0x04
 #define BSDB_MAPDETAIL	0x08
 #define	BSDB_ALL_ACCESS	0x10
 extern int bus_space_debug;
 
 #define BSHDB_ACCESS	0x01
 #define BSHDB_NO_ACCESS	0x02
 
 #if defined(BUS_SPACE_DEBUG)
-#ifndef _MACHINE_BUS_H_
+#ifndef __SYSTM_H__
 #include <sys/systm.h>
 #endif
 #define BUS_SPACE_PRINTF(l, s) do {				\
 	if(bus_space_debug & (l)) printf s;			\
 } while(0)
 #define BUS_SPACE_TRACE(t, h, s) do {				\
 	if ( (((bus_space_debug & BSDB_ALL_ACCESS) != 0) &&	\
 		(((h).bh_flags & BSHDB_NO_ACCESS) == 0)) ||	\
 	     (((bus_space_debug & BSDB_ACCESS) != 0) &&		\
 		(((h).bh_flags & BSHDB_ACCESS) != 0)))		\
 		printf s;					\
 	} while(0)
 #define BUS_SPACE_SET_FLAGS(t, h, f) ((h).bh_flags |= (f))
 #define BUS_SPACE_CLEAR_FLAGS(t, h, f) ((h).bh_flags &= ~(f))
 #define BUS_SPACE_FLAG_DECL(s)	int s
 #define BUS_SPACE_SAVE_FLAGS(t, h, s) (s = (h).bh_flags)
 #define BUS_SPACE_RESTORE_FLAGS(t, h, s) (s = (h).bh_flags)
 #define BUS_SPACE_ASSERT(t, h, o, n) do {			\
 	if (bus_space_debug & BSDB_ASSERT)			\
 		bus_space_assert(t, &(h), o, n);		\
 	} while(0)