Enable printf format argument checking.

The original attempt missed the fact that Print is a member function,
so the first argument is the implicit 'this'.

Change-Id: I963b668c5432804c767f0a2e3ef7dea5978a1218
diff --git a/adb_install.cpp b/adb_install.cpp
index ed15938..9e605e2 100644
--- a/adb_install.cpp
+++ b/adb_install.cpp
@@ -109,7 +109,7 @@
                 sleep(1);
                 continue;
             } else {
-                ui->Print("\nTimed out waiting for package.\n\n", strerror(errno));
+                ui->Print("\nTimed out waiting for package.\n\n");
                 result = INSTALL_ERROR;
                 kill(child, SIGKILL);
                 break;
diff --git a/recovery.cpp b/recovery.cpp
index 2f8654a..1726a22 100644
--- a/recovery.cpp
+++ b/recovery.cpp
@@ -844,7 +844,7 @@
 
     char* path = browse_directory(SDCARD_ROOT, device);
     if (path == NULL) {
-        ui->Print("\n-- No package file selected.\n", path);
+        ui->Print("\n-- No package file selected.\n");
         return INSTALL_ERROR;
     }
 
diff --git a/screen_ui.h b/screen_ui.h
index 210fd3e..82647ac 100644
--- a/screen_ui.h
+++ b/screen_ui.h
@@ -47,11 +47,11 @@
     bool WasTextEverVisible();
 
     // printing messages
-    void Print(const char* fmt, ...); // __attribute__((format(printf, 1, 2)));
+    void Print(const char* fmt, ...) __printflike(2, 3);
 
     // menu display
     void StartMenu(const char* const * headers, const char* const * items,
-                           int initial_selection);
+                   int initial_selection);
     int SelectMenu(int sel);
     void EndMenu();
 
diff --git a/ui.h b/ui.h
index 31a8a7f..a0580b7 100644
--- a/ui.h
+++ b/ui.h
@@ -63,7 +63,7 @@
 
     // Write a message to the on-screen log (shown if the user has
     // toggled on the text display).
-    virtual void Print(const char* fmt, ...) = 0; // __attribute__((format(printf, 1, 2))) = 0;
+    virtual void Print(const char* fmt, ...) __printflike(2, 3) = 0;
 
     // --- key handling ---