include: move busfault.h out of public include dir

this header is isn't public, so it's more appropriate, where the actual
code is, which is the os/ directory.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1337>

Xext/shm.c

@@ -43,6 +43,9 @@ in this Software without prior written authorization from The Open Group.
 #include <fcntl.h>
 #include <X11/X.h>
 #include <X11/Xproto.h>
+
+#include "os/busfault.h"
+
 #include "misc.h"
 #include "os.h"
 #include "dixstruct.h"
@@ -59,7 +62,6 @@ in this Software without prior written authorization from The Open Group.
 #include <X11/Xfuncproto.h>
 #include <sys/mman.h>
 #include "protocol-versions.h"
-#include "busfault.h"
 
 /* Needed for Solaris cross-zone shared memory extension */
 #ifdef HAVE_SHMCTL64

os/WaitFor.c

@@ -65,6 +65,7 @@ SOFTWARE.
 #include <X11/X.h>
 
 #include "dix/dix_priv.h"
+#include "os/busfault.h"
 
 #include "misc.h"
 #include "osdep.h"
@@ -73,7 +74,6 @@ SOFTWARE.
 #ifdef DPMSExtension
 #include "dpmsproc.h"
 #endif
-#include "busfault.h"
 
 #ifdef WIN32
 /* Error codes from windows sockets differ from fileio error codes  */

os/busfault.c

@@ -26,8 +26,10 @@
 
 #include <X11/Xos.h>
 #include <X11/Xdefs.h>
+
+#include "os/busfault.h"
+
 #include "misc.h"
-#include <busfault.h>
 #include <list.h>
 #include <stddef.h>
 #include <stdlib.h>

os/busfault.h

@@ -25,6 +25,8 @@
 
 #include <dix-config.h>
 
+#include <X11/Xdefs.h>
+
 #ifdef HAVE_SIGACTION
 
 #include <sys/types.h>

os/osinit.c

@@ -63,6 +63,8 @@ SOFTWARE.
 #include <execinfo.h>
 #endif
 
+#include "os/busfault.h"
+
 #include "misc.h"
 
 #include "dixstruct.h"
@@ -158,8 +160,6 @@ OsSigHandler(int signo)
 }
 #endif /* !WIN32 || __CYGWIN__ */
 
-#include "busfault.h"
-
 void
 OsInit(void)
 {