envsetup: Clean up for install[boot|recovery]

* Remove the files from device after installation

Change-Id: I52dc60c22abde972a066b879b3a74459261966e5
diff --git a/build/envsetup.sh b/build/envsetup.sh
index b0c70ad..d10c54b 100644
--- a/build/envsetup.sh
+++ b/build/envsetup.sh
@@ -370,6 +370,7 @@
             adb shell chmod 644 /system/lib/modules/*
         fi
         adb shell dd if=/cache/boot.img of=$PARTITION
+        adb shell rm -rf /cache/boot.img
         echo "Installation complete."
     else
         echo "The connected device does not appear to be $LINEAGE_BUILD, run away!"
@@ -410,6 +411,7 @@
     then
         adb push $OUT/recovery.img /cache/
         adb shell dd if=/cache/recovery.img of=$PARTITION
+        adb shell rm -rf /cache/recovery.img
         echo "Installation complete."
     else
         echo "The connected device does not appear to be $LINEAGE_BUILD, run away!"