Improve handling of shell symlink in recovery ramdisk

Change-Id: I06351f8ecdfe5b119bbae0d6800258adef844c66
diff --git a/gui/Android.mk b/gui/Android.mk
index 6134e3b..1ddab5e 100644
--- a/gui/Android.mk
+++ b/gui/Android.mk
@@ -101,26 +101,21 @@
 
 TWRP_RES_LOC := $(commands_recovery_local_path)/gui/devices
 TWRP_RES_GEN := $(intermediates)/twrp
-
 ifneq ($(TW_USE_TOOLBOX), true)
-$(TWRP_RES_GEN):
-	mkdir -p $(TARGET_RECOVERY_ROOT_OUT)/res/
-	cp -fr $(TWRP_RES_LOC)/common/res/* $(TARGET_RECOVERY_ROOT_OUT)/res/
-	cp -fr $(TWRP_RES_LOC)/$(DEVICE_RESOLUTION)/res/* $(TARGET_RECOVERY_ROOT_OUT)/res/
-	mkdir -p $(TARGET_RECOVERY_ROOT_OUT)/sbin/
-	ln -sf /sbin/busybox $(TARGET_RECOVERY_ROOT_OUT)/sbin/sh
-	ln -sf /sbin/pigz $(TARGET_RECOVERY_ROOT_OUT)/sbin/gzip
-	ln -sf /sbin/unpigz $(TARGET_RECOVERY_ROOT_OUT)/sbin/gunzip
+	TWRP_SH_TARGET := /sbin/busybox
 else
+	TWRP_SH_TARGET := /sbin/mksh
+endif
+
 $(TWRP_RES_GEN):
 	mkdir -p $(TARGET_RECOVERY_ROOT_OUT)/res/
 	cp -fr $(TWRP_RES_LOC)/common/res/* $(TARGET_RECOVERY_ROOT_OUT)/res/
 	cp -fr $(TWRP_RES_LOC)/$(DEVICE_RESOLUTION)/res/* $(TARGET_RECOVERY_ROOT_OUT)/res/
 	mkdir -p $(TARGET_RECOVERY_ROOT_OUT)/sbin/
-	ln -sf /sbin/mksh $(TARGET_RECOVERY_ROOT_OUT)/sbin/sh
+	ln -sf $(TWRP_SH_TARGET) $(TARGET_RECOVERY_ROOT_OUT)/sbin/sh
 	ln -sf /sbin/pigz $(TARGET_RECOVERY_ROOT_OUT)/sbin/gzip
 	ln -sf /sbin/unpigz $(TARGET_RECOVERY_ROOT_OUT)/sbin/gunzip
-endif
+
 
 LOCAL_GENERATED_SOURCES := $(TWRP_RES_GEN)
 LOCAL_SRC_FILES := twrp $(TWRP_RES_GEN)