lttng-tools: disable patching our libtool.m4

lttng-tools: disable patching our libtool.m4

Twelve years ago, libtool on Debian had a patch that meant it failed to
cross-compile lttng-tools correctly. The solution at the time was to
sed libtool.m4 whilst configure was being ran[1], which (assuming it
patches the correct file) results in a re-execution of configure during
do_compile.

This behaviour is undesired as we don't patch libtool in the way that
this fixup is needed (the sed only changes Haiku OS codepaths), so
disable it.

[1] https://github.com/lttng/lttng-tools/commit/6bd5984c2b1b1037e0345bbac3506b5503fe01bd

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>