[LIB]: export radix_tree_preload()

XFS filestreams functionality uses radix trees and the preload
functions. XFS can be built as a module and hence we need
radix_tree_preload() exported. radix_tree_preload_end() is a
static inline, so it doesn't need exporting.
Signed-Off-By: Dave Chinner <dgc@sgi.com>
Signed-Off-By: Tim Shimmin <tes@sgi.com>

lib/radix-tree.c

@@ -151,6 +151,7 @@ int radix_tree_preload(gfp_t gfp_mask)
 out:
 	return ret;
 }
+EXPORT_SYMBOL(radix_tree_preload);
 
 static inline void tag_set(struct radix_tree_node *node, unsigned int tag,
 		int offset)