Prevent nullptr derefence on failed allocation
diff --git a/fishhook.c b/fishhook.c
index 3f929c6..a4df70b 100644
--- a/fishhook.c
+++ b/fishhook.c
@@ -186,7 +186,7 @@
     struct rebindings_entry *rebindings_head = NULL;
     int retval = prepend_rebindings(&rebindings_head, rebindings, rebindings_nel);
     rebind_symbols_for_image(rebindings_head, (const struct mach_header *) header, slide);
-    if (rebindings_head->rebindings) {
+    if (rebindings_head) {
       free(rebindings_head->rebindings);
     }
     free(rebindings_head);