Do not duplicate reboot.c

Change-Id: I2ed41ffd14372bec9e18865cf299e15abc67d689
diff --git a/Android.mk b/Android.mk
index dcd948a..a59fedf 100644
--- a/Android.mk
+++ b/Android.mk
@@ -18,7 +18,7 @@
     mounts.c \
     extendedcommands.c \
     nandroid.c \
-    reboot.c \
+    ../../system/core/toolbox/reboot.c \
     edifyscripting.c \
     setprop.c