fastboot: remove command queue

There is little advantage and increasingly much disadvantage to
queueing up fastboot commands before executing them.  This change
removes the queue in the most simple way possible to enable further
clean up.

Test: fastboot works
Change-Id: I9abab05df07ed167dbe6a42e1eb9eab8f8d4f157
diff --git a/fastboot/fastboot_driver.cpp b/fastboot/fastboot_driver.cpp
index f9e640a..4a14131 100644
--- a/fastboot/fastboot_driver.cpp
+++ b/fastboot/fastboot_driver.cpp
@@ -97,9 +97,9 @@
     return RawCommand("reboot-" + target, response, info);
 }
 
-RetCode FastBootDriver::SetActive(const std::string& part, std::string* response,
+RetCode FastBootDriver::SetActive(const std::string& slot, std::string* response,
                                   std::vector<std::string>* info) {
-    return RawCommand(Commands::SET_ACTIVE + part, response, info);
+    return RawCommand(Commands::SET_ACTIVE + slot, response, info);
 }
 
 RetCode FastBootDriver::FlashPartition(const std::string& part, const std::vector<char>& data) {