Add missing escaping in makefile.

(Causing libart-compiler-.so in place of libart-compiler-X86.so.)

Change-Id: I4551c2e8fdfd2f6801a8516b503de495813a5c69
diff --git a/build/Android.libart-compiler.mk b/build/Android.libart-compiler.mk
index 88b280a..a899341 100644
--- a/build/Android.libart-compiler.mk
+++ b/build/Android.libart-compiler.mk
@@ -77,15 +77,15 @@
   endif
   LOCAL_CPP_EXTENSION := $(ART_CPP_EXTENSION)
   ifeq ($$(art_ndebug_or_debug),ndebug)
-    LOCAL_MODULE := libart-compiler-$(libart_compiler_arch)
+    LOCAL_MODULE := libart-compiler-$$(libart_compiler_arch)
   else # debug
-    LOCAL_MODULE := libartd-compiler-$(libart_compiler_arch)
+    LOCAL_MODULE := libartd-compiler-$$(libart_compiler_arch)
   endif
 
   LOCAL_MODULE_TAGS := optional
   LOCAL_MODULE_CLASS := SHARED_LIBRARIES
 
-  LOCAL_SRC_FILES := $(libart_compiler_src_files)
+  LOCAL_SRC_FILES := $$(libart_compiler_src_files)
   ifeq ($$(art_target_or_host),target)
     LOCAL_CFLAGS := $(ART_TARGET_CFLAGS)
   else # host
@@ -113,7 +113,7 @@
   endif
 
   # TODO: temporary hack for testing.
-  ifeq ($(libart_compiler_arch),MIPS)
+  ifeq ($$(libart_compiler_arch),MIPS)
     LOCAL_CFLAGS += -D__mips_hard_float
   endif