Replace MALLOC_IMPL with MALLOC_SVELTE.

Bug: http://b/26390299
Change-Id: I665f64bff4d598607e1eb7c4078819fe1d400feb
diff --git a/libc/Android.mk b/libc/Android.mk
index 83e1fb5..6e5ae62 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -645,7 +645,7 @@
   libc_common_cflags += -DDEBUG
 endif
 
-ifeq ($(MALLOC_IMPL),dlmalloc)
+ifeq ($(MALLOC_SVELTE),true)
   libc_common_cflags += -DUSE_DLMALLOC
   libc_malloc_src := bionic/dlmalloc.c
 else
@@ -1206,7 +1206,7 @@
 LOCAL_WHOLE_STATIC_LIBRARIES_arm := libc_aeabi
 LOCAL_CXX_STL := none
 
-ifneq ($(MALLOC_IMPL),dlmalloc)
+ifneq ($(MALLOC_SVELTE),true)
 LOCAL_WHOLE_STATIC_LIBRARIES += libjemalloc
 endif
 
@@ -1343,7 +1343,7 @@
 LOCAL_ADDITIONAL_DEPENDENCIES := $(libc_common_additional_dependencies)
 LOCAL_WHOLE_STATIC_LIBRARIES := libc_common
 
-ifneq ($(MALLOC_IMPL),dlmalloc)
+ifneq ($(MALLOC_SVELTE),true)
 LOCAL_WHOLE_STATIC_LIBRARIES += libjemalloc
 endif
 
@@ -1409,7 +1409,7 @@
 LOCAL_SHARED_LIBRARIES := libdl
 LOCAL_WHOLE_STATIC_LIBRARIES := libc_common
 
-ifneq ($(MALLOC_IMPL),dlmalloc)
+ifneq ($(MALLOC_SVELTE),true)
 LOCAL_WHOLE_STATIC_LIBRARIES += libjemalloc
 endif