Use libtool correctly.

This is the only package I've seen that tries to use a system-installed libtool
program.

--- srecord-1.64/Makefile.in	2014-06-22 06:31:46.000000000 +0100
+++ srecord-1.64/Makefile.in	2025-08-15 06:37:45.471989409 +0100
@@ -36,6 +36,7 @@
 #
 srcdir = @srcdir@
 VPATH = @srcdir@
+top_builddir = @srcdir@
 
 #
 # the name of the install program to use
--- srecord-1.64/etc/configure.ac	2014-06-22 06:31:46.000000000 +0100
+++ srecord-1.64/etc/configure.ac	2025-08-15 06:34:38.747275475 +0100
@@ -161,42 +161,7 @@
 dnl!
 dnl!  Now look for libtool.
 dnl!
-AC_CHECK_PROGS(LIBTOOL, libtool)
-if test -z "$LIBTOOL"
-then
-  AC_MSG_RESULT([
-        You must have GNU Libtool installed to build srecord.
-        Homepage: http://www.gnu.org/software/libtool/])
-  OK=no
-  if apt-get --version > /dev/null 2> /dev/null; then
-    AC_MSG_RESULT([
-        The following command may be used to install it:
-        sudo apt-get install libtool
-    ])
-    OK=yes
-  fi
-  if yum --version > /dev/null 2> /dev/null; then
-    AC_MSG_RESULT([
-        The following command may be used to install it:
-        sudo yum install libtool
-    ])
-    OK=yes
-  fi
-  if pkg_info -a > /dev/null 2> /dev/null; then
-    AC_MSG_RESULT([
-        The following command may be used to install it:
-        sudo pkg_add -r libtool
-    ])
-    OK=yes
-  fi
-  if test "$OK" != "yes"; then
-    AC_MSG_RESULT([
-        If you are using a package based install, you will need the
-        libtool package.
-    ])
-  fi
-  exit 1
-fi
+LT_INIT
 
 dnl
 dnl     If the soelim program exists, and understands the -I option,