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)
diff --git a/src/eval.c b/src/eval.c
index 3f2a33a..5c5fd2f 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -9439,7 +9439,7 @@
     // Get the script file name: replace '#' with '/', append ".vim".
     scriptname = alloc(STRLEN(name) + 14);
     if (scriptname == NULL)
-	return FALSE;
+	return NULL;
     STRCPY(scriptname, "autoload/");
     STRCAT(scriptname, name);
     for (p = scriptname + 9; (p = vim_strchr(p, AUTOLOAD_CHAR)) != NULL;
@@ -9469,6 +9469,8 @@
 	return FALSE;
 
     tofree = scriptname = autoload_name(name);
+    if (scriptname == NULL)
+	return FALSE;
 
     /* Find the name in the list of previously loaded package names.  Skip
      * "autoload/", it's always the same. */
diff --git a/src/version.c b/src/version.c
index b7ceb36..019ce25 100644
--- a/src/version.c
+++ b/src/version.c
@@ -766,6 +766,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1894,
+/**/
     1893,
 /**/
     1892,