ART: Fix up dex2oat usage message

Follow-up to commit cac31ad4c43a24a959a4d3652b8b46538bdc8c53.

Test: none
Change-Id: I6b65085aeec15ececf2368110c50002bb392af66
diff --git a/dex2oat/dex2oat.cc b/dex2oat/dex2oat.cc
index 29228a3..9fa7f69 100644
--- a/dex2oat/dex2oat.cc
+++ b/dex2oat/dex2oat.cc
@@ -452,8 +452,8 @@
   UsageError("  --compact-dex-level=none|fast: None avoids generating compact dex, fast");
   UsageError("      generates compact dex with low compile time.");
   UsageError("");
-  UsageError("  --deduplicate-code|--no-deduplicate-code: enable|disable code deduplication.");
-  UsageError("      Deduplicated code will have an arbitrary symbol tagged with [DEDUPED].");
+  UsageError("  --deduplicate-code=true|false: enable|disable code deduplication. Deduplicated");
+  UsageError("      code will have an arbitrary symbol tagged with [DEDUPED].");
   UsageError("");
   std::cerr << "See log for usage error information\n";
   exit(EXIT_FAILURE);