patch 8.2.0881: compiler warning for argument type

Problem:    Compiler warning for argument type.
Solution:   Add type cast. (Mike Williams)
diff --git a/src/ops.c b/src/ops.c
index 14d1ed4..ea71edb 100644
--- a/src/ops.c
+++ b/src/ops.c
@@ -2077,7 +2077,7 @@
 	currsize = (int)STRLEN(curr);
     }
 
-    ml_replace_len(curwin->w_cursor.lnum, newp, newp_len, TRUE, FALSE);
+    ml_replace_len(curwin->w_cursor.lnum, newp, (colnr_T)newp_len, TRUE, FALSE);
 
     if (setmark && !cmdmod.lockmarks)
     {