ART: Fix valgrind Makefile

Add a missing dependency that lead to runtime errors.

Change-Id: Idbaed6bcc56a644713f10847f8600dc0f962202f
diff --git a/build/Android.gtest.mk b/build/Android.gtest.mk
index 0876cc0..5052187 100644
--- a/build/Android.gtest.mk
+++ b/build/Android.gtest.mk
@@ -393,7 +393,7 @@
 
 
 .PHONY: valgrind-$$(gtest_rule)
-valgrind-$$(gtest_rule): $$(gtest_deps) $(ART_VALGRIND_DEPENDENCIES)
+valgrind-$$(gtest_rule): $$(gtest_exe) $$(gtest_deps) $(ART_VALGRIND_DEPENDENCIES)
 	$(hide) $$(call ART_TEST_SKIP,$$@) && \
 	  VALGRIND_LIB=$(HOST_OUT)/lib64/valgrind \
 	  $(HOST_OUT_EXECUTABLES)/valgrind --leak-check=full --error-exitcode=1 $$< && \