patch 9.1.0649: Wrong comment for "len" argument of call_simple_func()

Problem:  Wrong comment for "len" argument of call_simple_func().
Solution: Remove the "or -1 to use strlen()".  Also change its type to
          size_t to remove one cast. (zeertzjq)

closes: #15410

Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index 3ca6001..76b00a9 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    649,
+/**/
     648,
 /**/
     647,