build: Don't call make_recovery_patch if there's no recovery.

Change-Id: Iea1bd529eca9cd607da3b420bc4287f95c18219d
diff --git a/core/Makefile b/core/Makefile
index 2f75568..89d0431 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -1527,8 +1527,10 @@
 	$(hide) echo "full_recovery_image=true" >> $(zip_root)/META/misc_info.txt
 endif
 	$(call generate-userimage-prop-dictionary, $(zip_root)/META/misc_info.txt)
+ifneq ($(INSTALLED_RECOVERYIMAGE_TARGET),)
 	$(hide) PATH=$(foreach p,$(INTERNAL_USERIMAGES_BINARY_PATHS),$(p):)$$PATH MKBOOTIMG=$(MKBOOTIMG) \
 	    ./build/tools/releasetools/make_recovery_patch $(zip_root) $(zip_root)
+endif
 	@# Zip everything up, preserving symlinks
 	$(hide) (cd $(zip_root) && zip -qry ../$(notdir $@) .)
 	@# Run fs_config on all the system, vendor, boot ramdisk,