don't say "install complete" when it really isn't

Change the recovery UI so that when there is a hboot or radio update
pending (which the user most do a home+back reboot to actually
install), the UI tells them so, instead of saying "Install from sdcard
complete."
diff --git a/recovery.c b/recovery.c
index a0bae97..e329db9 100644
--- a/recovery.c
+++ b/recovery.c
@@ -375,7 +375,12 @@
                     } else if (!ui_text_visible()) {
                         return;  // reboot if logs aren't visible
                     } else {
-                      ui_print("Install from sdcard complete.\n");
+                      if (firmware_update_pending()) {
+                        ui_print("\nReboot via home+back or menu\n"
+                                 "to complete installation.\n");
+                      } else {
+                        ui_print("\nInstall from sdcard complete.\n");
+                      }
                     }
                     break;
             }