radix-tree: fix typo

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 2e8c6f7..60c1036 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -1110,7 +1110,7 @@
 	 * because RADIX_TREE_MAP_SHIFT < BITS_PER_LONG.
 	 *
 	 * This condition also used by radix_tree_next_slot() to stop
-	 * contiguous iterating, and forbid swithing to the next chunk.
+	 * contiguous iterating, and forbid switching to the next chunk.
 	 */
 	index = iter->next_index;
 	if (!index && iter->index)