patch 8.1.2353: build failure on FreeBSD

Problem:    Build failure on FreeBSD.
Solution:   Change #ifdef to only check for Linux-like systems.
diff --git a/src/version.c b/src/version.c
index 4c7c380..0e2f7fa 100644
--- a/src/version.c
+++ b/src/version.c
@@ -738,6 +738,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2353,
+/**/
     2352,
 /**/
     2351,