net-tools: Fix do_patch to be re-executable

This recipe's do_patch was not able to be re-executed due to its custom
patching functions. This fixes things so that it can be re-executed.

It also fixes the unpack task re-execution by ensuring ${S} is clean
before the unpack starts.

[YOCTO #2194]

(From OE-Core rev: 1cfddb17e0c2576e55f62c10612e7cbd73e5ac5e)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-extended/net-tools/net-tools_1.60-23.bb

@@ -31,11 +31,19 @@ PARALLEL_MAKE = ""
 # up all previously applied patches in the start
 nettools_do_patch() {
 	cd ${S}
-	patch -p1 < ${WORKDIR}/${BPN}_${PV}.diff
+	quilt pop -a || true
+	if [ -d ${S}/.pc-nettools ]; then
+		mv ${S}/.pc-nettools ${S}/.pc
+		QUILT_PATCHES=${S}/debian/patches quilt pop -a
+		rm -rf ${S}/.pc ${S}/debian
+	fi
+	patch -p1 < ${WORKDIR}/${BPN}_${PV}.diff	
 	QUILT_PATCHES=${S}/debian/patches quilt push -a
-	rm -rf ${S}/patches ${S}/.pc
+	mv ${S}/.pc ${S}/.pc-nettools
 }
 
+do_unpack[cleandirs] += "${S}"
+
 # We invoke base do_patch at end, to incorporate any local patch
 python do_patch() {
 	bb.build.exec_func('nettools_do_patch', d)