ART: Remove unnecessary include of linear_alloc.h.

Change-Id: Ic6648f1cc55bc75cd58bc81824cd7f0194ab78ce
diff --git a/runtime/length_prefixed_array.h b/runtime/length_prefixed_array.h
index d9bc656..0ff6d7a 100644
--- a/runtime/length_prefixed_array.h
+++ b/runtime/length_prefixed_array.h
@@ -19,7 +19,6 @@
 
 #include <stddef.h>  // for offsetof()
 
-#include "linear_alloc.h"
 #include "stride_iterator.h"
 #include "base/bit_utils.h"
 #include "base/casts.h"