tools: Fix math.h breakage

Commit 98e1385ef2 ("include/linux/radix-tree.h: replace kernel.h with
the necessary inclusions") broke the radix tree test suite in two
different ways; first by including math.h which didn't exist in the
tools directory, and second by removing an implicit include of
spinlock.h before lockdep.h.  Fix both issues.

Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tools/include/linux/math.h

@@ -0,0 +1,25 @@
+#ifndef _TOOLS_MATH_H
+#define _TOOLS_MATH_H
+
+/*
+ * This looks more complex than it should be. But we need to
+ * get the type for the ~ right in round_down (it needs to be
+ * as wide as the result!), and we want to evaluate the macro
+ * arguments just once each.
+ */
+#define __round_mask(x, y) ((__typeof__(x))((y)-1))
+#define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
+#define round_down(x, y) ((x) & ~__round_mask(x, y))
+
+#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
+
+#ifndef roundup
+#define roundup(x, y) (                                \
+{                                                      \
+	const typeof(y) __y = y;		       \
+	(((x) + (__y - 1)) / __y) * __y;	       \
+}                                                      \
+)
+#endif
+
+#endif