patch 9.1.0957: MS-Windows: conversion warnings

Problem:  MS-Windows: conversion warnings
Solution: add explicit type casts (Yegappan Lakshmanan)

closes: #16288

Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/filepath.c b/src/filepath.c
index 3dd71bc..1ac2f86 100644
--- a/src/filepath.c
+++ b/src/filepath.c
@@ -675,7 +675,7 @@
 			    if (s != NULL)
 			    {
 				*fnamep = s;
-				*fnamelen = slen;
+				*fnamelen = (int)slen;
 				vim_free(*bufp);
 				*bufp = s;
 				didit = TRUE;