2.6.27+ portability changes

- Added SPL_AC_3ARGS_ON_EACH_CPU configure check to determine
  if the older 4 argument version of on_each_cpu() should be
  used or the new 3 argument version.  The retry argument was
  dropped in the new API which was never used anyway.
- Updated work queue compatibility wrappers.  The old way this
  worked was to pass a data point when initialized the workqueue.
  The new API assumed the work item is embedding in a structure
  and we us container_of() to find that data pointer.
- Updated skc->skc_flags to be an unsigned long which is now
  type checked in the bit operations.  This silences the warnings.
- Updated autogen products and splat tests accordingly

config/spl-build.m4

@@ -686,3 +686,22 @@ AC_DEFUN([SPL_AC_DIV64_64], [
 		AC_MSG_RESULT(no)
 	])
 ])
+
+dnl #
+dnl # 2.6.27 API change,
+dnl # on_each_cpu() uses 3 args, no 'retry' argument
+dnl #
+AC_DEFUN([SPL_AC_3ARGS_ON_EACH_CPU], [
+	AC_MSG_CHECKING([whether on_each_cpu() wants 3 args])
+	SPL_LINUX_TRY_COMPILE([
+		#include <linux/smp.h>
+	],[
+		on_each_cpu(NULL, NULL, 0);
+	],[
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(HAVE_3ARGS_ON_EACH_CPU, 1,
+		          [on_each_cpu wants 3 args])
+	],[
+		AC_MSG_RESULT(no)
+	])
+])