Fix -Wunused-variable compiler warning

Test: presubmit
Change-Id: I63b1625decd3dcdb9f405c8825203e04810c282c
diff --git a/fastboot/task.cpp b/fastboot/task.cpp
index 25c5a6e..0947ff9 100644
--- a/fastboot/task.cpp
+++ b/fastboot/task.cpp
@@ -224,7 +224,7 @@
     auto remove_if_callback = [&](const auto& task) -> bool {
         if (auto flash_task = task->AsFlashTask()) {
             return helper->WillFlash(flash_task->GetPartitionAndSlot());
-        } else if (auto update_super_task = task->AsUpdateSuperTask()) {
+        } else if (task->AsUpdateSuperTask()) {
             return true;
         } else if (auto reboot_task = task->AsRebootTask()) {
             if (reboot_task->GetTarget() == "fastboot") {