[newlib-cygwin] Cygwin: Fix configure help for --{en, dis}able-doc option

[Jon TURNEY]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=4a7461a07b5af77dcbf9bae6e2a27141eb189f79

commit 4a7461a07b5af77dcbf9bae6e2a27141eb189f79
Author: Jon Turney <jon.turney@dronecode.org.uk>
Date:   Tue Jan 18 16:26:36 2022 +0000

    Cygwin: Fix configure help for --{en,dis}able-doc option
    
    Report '--disable-doc' in 'configure --help', as enable is the default.

Diff:
---
 winsup/configure.ac | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/winsup/configure.ac b/winsup/configure.ac
index 4ae20509a..b8d2100db 100644
--- a/winsup/configure.ac
+++ b/winsup/configure.ac
@@ -89,7 +89,7 @@ AC_SUBST(TLSOFFSETS_H)
 AM_CONDITIONAL(TARGET_X86_64, [test $target_cpu = "x86_64"])
 
 AC_ARG_ENABLE(doc,
-	      [AS_HELP_STRING([--enable-doc], [Build documentation])],,
+	      [AS_HELP_STRING([--disable-doc], [do not build documentation])],,
 	      enable_doc=yes)
 AM_CONDITIONAL(BUILD_DOC, [test $enable_doc != "no"])