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/firmware.c b/firmware.c
index 34b2918..e2e4fe6 100644
--- a/firmware.c
+++ b/firmware.c
@@ -39,6 +39,10 @@
     return 0;
 }
 
+// Return true if there is a firmware update pending.
+int firmware_update_pending() {
+  return update_data != NULL && update_length > 0;
+}
 
 /* Bootloader / Recovery Flow
  *
diff --git a/firmware.h b/firmware.h
index f3f7aab..aeb8f97 100644
--- a/firmware.h
+++ b/firmware.h
@@ -23,6 +23,9 @@
  */
 int remember_firmware_update(const char *type, const char *data, int length);
 
+/* Returns true if a firmware update has been saved. */
+int firmware_update_pending();
+
 /* If an update was saved, reboot into the bootloader now to install it.
  * Returns 0 if no radio image was defined, nonzero on error,
  * doesn't return at all on success...
diff --git a/install.c b/install.c
index 4dcfe75..e7db2a8 100644
--- a/install.c
+++ b/install.c
@@ -105,7 +105,7 @@
         return INSTALL_ERROR;
     }
 
-    ui_print("Installation complete.\n");
+    LOGI("Installation complete.\n");
     return INSTALL_SUCCESS;
 }
 
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;
             }