patch 9.0.1561: display wrong when moving cursor to above the top line

Problem:    Display wrong when moving cursor to above the top line and
            'smoothscroll' is set.
Solution:   Call adjust_skipcol() in more places and make it work better.
            (Luuk van Baal, closes #12395)
diff --git a/src/textobject.c b/src/textobject.c
index d77ec96..b315d03 100644
--- a/src/textobject.c
+++ b/src/textobject.c
@@ -472,6 +472,7 @@
 finished:
 	stop = FALSE;
     }
+    adjust_skipcol();
     return OK;
 }
 
@@ -598,6 +599,7 @@
 		return OK;
 	}
     }
+    adjust_skipcol();
     return OK;
 }