lib/interval-tree: correct comment wrt generic flavor

interval_tree.h _is_ the generic flavor.

Link: http://lkml.kernel.org/r/20170719014603.19029-13-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/interval_tree_generic.h

@@ -33,7 +33,7 @@
  * ITSTATIC:   'static' or empty
  * ITPREFIX:   prefix to use for the inline tree definitions
  *
- * Note - before using this, please consider if non-generic version
+ * Note - before using this, please consider if generic version
  * (interval_tree.h) would work for you...
  */