r.accumulate: Correct direction raster name (#960)

src/raster/r.accumulate/r.accumulate.html

@@ -152,10 +152,10 @@ <h3>Stream network delineation</h3>
 <em>r.stream.extract</em>) and <i>streams_new</i> (blue from
 <em>r.accumulate</em>) vector maps present different stream paths. The numbers
 show cell elevations (<i>elevation</i> map), and the yellow
-(<i>drain_directions</i> map) and green (<i>drain_directions_2</i> map) arrows
-represent flow directions generated by <em>r.watershed</em> with <b>-s</b> flag
-and <em>r.stream.extract</em>, respectively. Note that the two flow direction
-maps are different.
+(<i>drain_directions</i> map) and green (<i>drain_directions_extract</i> map)
+arrows represent flow directions generated by <em>r.watershed</em> with
+<b>-s</b> flag and <em>r.stream.extract</em>, respectively. Note that the two
+flow direction maps are different.
 
 <p><img src="r_accumulate_nc_stream_comparison.png">