gitk: Fix mistype

Signed-off-by: Max Kirillov <max@max630.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/gitk b/gitk
index 33c3a6c..1f14796 100755
--- a/gitk
+++ b/gitk
@@ -7922,7 +7922,7 @@
     if {$diffseehere >= 0} {
 	mark_ctext_line [lindex [split $diffseehere .] 0]
     }
-    maybe_scroll_ctext ateof
+    maybe_scroll_ctext $ateof
 }
 
 proc getblobdiffline {bdf ids} {