SDL_rtf: libtool upgrade to 2.4.6 - 4/n: fix m4 quoting bug

From d636cf4c942f4c4a7f4d5e9dd47e532a53321c3a Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Thu, 2 Dec 2021 20:50:10 +0300
Subject: [PATCH] libtool upgrade to 2.4.6 - 4/n: fix m4 quoting bug

https://debbugs.gnu.org/cgi/bugreport.cgi?bug=41837
http://git.savannah.gnu.org/gitweb/?p=libtool.git;a=commitdiff;h=0904164dd5b57b3230dce04207738ce961591762
---
 acinclude/libtool.m4 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/acinclude/libtool.m4 b/acinclude/libtool.m4
index 0cec55c..ebb07d8 100644
--- a/acinclude/libtool.m4
+++ b/acinclude/libtool.m4
@@ -5039,7 +5039,7 @@ dnl Note also adjust exclude_expsyms for C++ above.
       _LT_TAGVAR(whole_archive_flag_spec, $1)=
     fi
     supports_anon_versioning=no
-    case `$LD -v | $SED -e 's/([^)]\+)\s\+//' 2>&1` in
+    case `$LD -v | $SED -e 's/([[^)]]\+)\s\+//' 2>&1` in
       *GNU\ gold*) supports_anon_versioning=yes ;;
       *\ [[01]].* | *\ 2.[[0-9]].* | *\ 2.10.*) ;; # catch versions < 2.11
       *\ 2.11.93.0.2\ *) supports_anon_versioning=yes ;; # RH7.3 ...