[binutils-gdb] fbsd-nat: Fix build failure with GCC 12

[Enze Li]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=d5fa6e8c6cb82b03f20dd521f70dcc7fefe573dc

commit d5fa6e8c6cb82b03f20dd521f70dcc7fefe573dc
Author: Enze Li <enze.li@hotmail.com>
Date:   Tue Sep 26 20:55:36 2023 +0800

    fbsd-nat: Fix build failure with GCC 12
    
    A user pointed out that the build failed on FreeBSD/amd64 with my last
    commit.  The problem is that I'm not using the proper way to tell the
    compiler that the variable has been "used".  This patch fixes this issue
    as suggested by John.  Pushed as obvious.
    
    Tested both on FreeBSD/amd64 and FreeBSD/aarch64 by rebuilding.
    
    Suggested-By: John Baldwin <jhb@FreeBSD.org>

Diff:
---
 gdb/fbsd-nat.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gdb/fbsd-nat.c b/gdb/fbsd-nat.c
index 81a77b3a60f..55a36f24025 100644
--- a/gdb/fbsd-nat.c
+++ b/gdb/fbsd-nat.c
@@ -2094,7 +2094,7 @@ fbsd_nat_target::detach (inferior *inf, int from_tty)
 		  }
 #else
 		  /* pacify gcc  */
-		  wptid = (void) null_ptid;
+		  (void) wptid;
 #endif
 		  sig = 0;
 		  break;