Add __attribute__((format(printf, a, b))) to printf like functions.

Fix potential string format bug.

Change-Id: Ie05aac53b2c45a48bd68e340b76ccb21edfd28b7
diff --git a/install.c b/install.c
index 37a4f07..35ba6ca 100644
--- a/install.c
+++ b/install.c
@@ -136,7 +136,7 @@
         } else if (strcmp(command, "ui_print") == 0) {
             char* str = strtok(NULL, "\n");
             if (str) {
-                ui_print(str);
+                ui_print("%s", str);
             } else {
                 ui_print("\n");
             }