Check return of init_keys() ip_address_changed: fix Coverity CID 484

changes/cov484

@@ -0,0 +1,4 @@
+  o Minor bugfixes:
+    - Report any failure in init_keys() calls done because our IP address
+      has changed. Spotted by Coverity Scan. Bugfix on 0.1.1.4-alpha;
+      fixes CID 484.

src/or/main.c

@@ -1378,7 +1378,8 @@ ip_address_changed(int at_interface)
   if (at_interface) {
     if (! server) {
       /* Okay, change our keys. */
-      init_keys();
+      if (init_keys()<0)
+        log_warn(LD_GENERAL, "Unable to rotate keys after IP change!");
     }
   } else {
     if (server) {