patch 8.1.0444: unnecessary check for NULL pointer

Problem:    Unnecessary check for NULL pointer.
Solution:   Remove check and call vim_free() directly.
diff --git a/src/version.c b/src/version.c
index 8f75fef..e7ce604 100644
--- a/src/version.c
+++ b/src/version.c
@@ -793,6 +793,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    444,
+/**/
     443,
 /**/
     442,