alsa-plugins: improve .la removal
Don't assume that the .la files are installed, because some libtool
alternatives don't install these.
Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit e92b24368b71e4b178f81097b2a8d141c3b65481)
Signed-off-by: Steve Sakoman <steve@sakoman.com>