fix typo

PRIATE -> PRIVATE

Test: m -j
Change-Id: I33bbdcefee8acb16e9d8fcdb4c86ce294b3c1762
diff --git a/core/prebuilt_internal.mk b/core/prebuilt_internal.mk
index c635ca5..94c2dcd 100644
--- a/core/prebuilt_internal.mk
+++ b/core/prebuilt_internal.mk
@@ -667,7 +667,7 @@
 $(my_exported_sdk_libs_file):
 	@echo "Export SDK libs $@"
 	$(hide) mkdir -p $(dir $@) && rm -f $@
-	$(if $(PRIATE_EXPORTED_SDK_LIBS),\
+	$(if $(PRIVATE_EXPORTED_SDK_LIBS),\
 		$(hide) echo $(PRIVATE_EXPORTED_SDK_LIBS) | tr ' ' '\n' > $@,\
 		$(hide) touch $@)