Retire KM_NODEBUG

Callers of kmem_alloc() which passed the KM_NODEBUG flag to suppress
the large allocation warning have been replaced by vmem_alloc() as
appropriate.  The updated vmem_alloc() call will not print a warning
regardless of the size of the allocation.

A careful reader will notice that not all callers have been changed
to vmem_alloc().  Some have only had the KM_NODEBUG flag removed.
This was possible because the default warning threshold has been
increased to 32k.  This is desirable because it minimizes the need
for Linux specific code changes.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>

include/sys/spa.h

@@ -29,6 +29,7 @@
 
 #include <sys/avl.h>
 #include <sys/zfs_context.h>
+#include <sys/kstat.h>
 #include <sys/nvpair.h>
 #include <sys/sysmacros.h>
 #include <sys/types.h>

include/sys/zfs_context.h

@@ -41,6 +41,7 @@
 #include <sys/bitmap.h>
 #include <sys/cmn_err.h>
 #include <sys/kmem.h>
+#include <sys/vmem.h>
 #include <sys/taskq.h>
 #include <sys/buf.h>
 #include <sys/param.h>
@@ -391,7 +392,6 @@ extern void kstat_set_raw_ops(kstat_t *ksp,
 #define	KM_SLEEP		UMEM_NOFAIL
 #define	KM_PUSHPAGE		KM_SLEEP
 #define	KM_NOSLEEP		UMEM_DEFAULT
-#define	KM_NODEBUG		0x0
 #define	KMC_NODEBUG		UMC_NODEBUG
 #define	KMC_KMEM		0x0
 #define	KMC_VMEM		0x0