Makefile: improve uninstall error handling

Introduce helper functions to handle uninstall errors gracefully.

Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>

tools/helpers.mk

@@ -0,0 +1,15 @@
+#
+# Copyright(c) 2021 Intel Corporation
+# SPDX-License-Identifier: BSD-3-Clause-Clear
+#
+
+define remove-file
+	@if [ -f ${1} ] || [ -L ${1} ]; then rm -rf ${1}; \
+	else echo "WARNING: Cannot find file ${1}"; fi
+endef
+
+define remove-directory
+	@if [ -d ${1} ]; then rm -rf ${1}; \
+	else echo "WARNING: Cannot find directory ${1}"; fi
+endef
+