patch 8.1.0952: compilation warnings when building the MS-Windows installer

Problem:    Compilation warnings when building the MS-Windows installer.
Solution:   Fix buffer sizes. (Yasuhiro Matsumoto, closes #3999)
diff --git a/src/uninstal.c b/src/uninstal.c
index 11b6c62..d0d0b06 100644
--- a/src/uninstal.c
+++ b/src/uninstal.c
@@ -321,8 +321,8 @@
     int		i;
     struct stat st;
     char	icon[BUFSIZE];
-    char	path[BUFSIZE];
-    char	popup_path[BUFSIZE];
+    char	path[MAX_PATH];
+    char	popup_path[MAX_PATH];
 
     /* The nsis uninstaller calls us with a "-nsis" argument. */
     if (argc == 2 && stricmp(argv[1], "-nsis") == 0)