syntax-check: fix remaining violations of sc_prohibit_test_const_follows_var.

* configure.ac, doc/libtool.texi: Swap operands and remove resulting
spurious characters.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>

configure.ac

diff --git a/configure.ac b/configure.ac
index 5772c71..517f706 100644
--- a/configure.ac
+++ b/configure.ac
@@ -114,7 +114,7 @@
 
 AC_ARG_ENABLE(ltdl-install,
     [AS_HELP_STRING([--disable-ltdl-install], [do not install libltdl])])
-if test "x${enable_ltdl_install+set}" != xset; then
+if test set != "${enable_ltdl_install+set}"; then
   enable_ltdl_install=yes
 fi
 

doc/libtool.texi

diff --git a/doc/libtool.texi b/doc/libtool.texi
index 93803ac..77d65bc 100644
--- a/doc/libtool.texi
+++ b/doc/libtool.texi
@@ -4756,7 +4756,7 @@
 LTDL_INIT
 
 # The lt_dladvise_init symbol was added with libtool-2.2
-if test "x$with_included_ltdl" != "xyes"; then
+if test yes != "$with_included_ltdl"; then
   save_CFLAGS=$CFLAGS
   save_LDFLAGS=$LDFLAGS
   CFLAGS="$CFLAGS $LTDLINCL"