zfs_context: remove misc unused

Sponsored-by: https://despairlabs.com/sponsor/
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Rob Norris <[email protected]>
Closes #17861

Author: robn

include/sys/zfs_context.h

@@ -77,7 +77,6 @@ extern "C" {
 #include <sys/zfs_context_os.h>
 #else /* _KERNEL || _STANDALONE */
 
-#define	_SYS_VFS_H
 #define	_SYS_SUNDDI_H
 
 #include <stdio.h>
@@ -206,7 +205,6 @@ typedef off_t loff_t;
 #define	CPU_SEQID	((uintptr_t)pthread_self() & (max_ncpus - 1))
 #define	CPU_SEQID_UNSTABLE	CPU_SEQID
 
-#define	NN_DIVISOR_1000	(1U << 0)
 #define	NN_NUMBUF_SZ	(6)
 
 extern int highbit64(uint64_t i);
@@ -218,20 +216,6 @@ extern int lowbit64(uint64_t i);
 extern int ddi_strtoull(const char *str, char **nptr, int base,
     u_longlong_t *result);
 
-/* ZFS Boot Related stuff. */
-
-struct _buf {
-	intptr_t	_fd;
-};
-
-struct bootstat {
-	uint64_t st_size;
-};
-
-#define	DDI_SLEEP	KM_SLEEP
-#define	ddi_log_sysevent(_a, _b, _c, _d, _e, _f, _g) \
-	sysevent_post_event(_c, _d, _b, "libzpool", _e, _f)
-
 /*
  * Kernel modules
  */