patch 8.1.0112: no error when using bad arguments with searchpair()

Problem:    No error when using bad arguments with searchpair().
Solution:   Add error messages.
diff --git a/src/version.c b/src/version.c
index 95332ca..06ed8ce 100644
--- a/src/version.c
+++ b/src/version.c
@@ -790,6 +790,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    112,
+/**/
     111,
 /**/
     110,