patch 9.1.1075: Vim9: len variable not used in compile_load()

Problem:  Vim9: length variable not used in compile_load()
Solution: use len instead of re-calculating the length
          (Hirohito Higashi)

closes: #16582

Signed-off-by: Hirohito Higashi <h.east.727@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/vim9expr.c b/src/vim9expr.c
index b765448..58ff395 100644
--- a/src/vim9expr.c
+++ b/src/vim9expr.c
@@ -796,7 +796,7 @@
 	int	    outer_loop_depth = -1;
 	int	    outer_loop_idx = -1;
 
-	name = vim_strnsave(*arg, end - *arg);
+	name = vim_strnsave(*arg, len);
 	if (name == NULL)
 	    return FAIL;