autotools: log when we're removing aclocal.m4

Some mysterious autotools errors are because upstream has a custom
aclocal.m4 that we're deleting it unless we know we're not even running
aclocal.  There's a case to be made for removing this deletion logic
on the grounds that aclocal should know what it is doing, but for now
make it clear that we're deleting a file by saying so in the task log.

(From OE-Core rev: d6efd938af8a8260ae464edf4388afea73293ec7)

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes-recipe/autotools.bbclass

@@ -193,6 +193,7 @@ autotools_do_configure() {
 		# like it was auto-generated.  Work around this by blowing it away
 		# by hand, unless the package specifically asked not to run aclocal.
 		if ! echo ${EXTRA_AUTORECONF} | grep -q "aclocal"; then
+			bbnote Removing existing aclocal.m4
 			rm -f aclocal.m4
 		fi
 		if [ -e configure.in ]; then