patch 8.1.1894: not checking for out-of-memory of autoload_name()

Problem:    Not checking for out-of-memory of autoload_name().
Solution:   Check for NULL. (Dominique Pelle, closes #4846)

src/version.c

@@ -765,6 +765,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1894,
 /**/
     1893,
 /**/