Fix build errors.

- boot_control: Removes unused variable.

Change-Id: Ib8b5f5bed54dcba8bd24eeb79927fffd422c0b4d
diff --git a/boot_control.cpp b/boot_control.cpp
index 7319f9a..899b6e2 100644
--- a/boot_control.cpp
+++ b/boot_control.cpp
@@ -526,7 +526,6 @@
 	int rc = -1;
 	int is_ufs = gpt_utils_is_ufs_device();
 	map<string, vector<string>>::iterator map_iter;
-	vector<string>::iterator string_iter;
 
 	if (boot_control_check_slot_sanity(module, slot)) {
 		ALOGE("%s: Bad arguments", __func__);