emacs-28 4802419 2/2: Fix compilation on MS-Windows

[Philipp Stephani]

branch: emacs-28
commit 480241983ea91e31ca4d757fe91df84d1d11d3c9
Author: Eli Zaretskii <eliz@gnu.org>
Commit: Philipp Stephani <phst@google.com>

    Fix compilation on MS-Windows
    
    * src/callproc.c (emacs_spawn) <fork_done>: Define the label only
    if USABLE_POSIX_SPAWN is defined, to avoid a compiler warning.
    
    (cherry picked from commit a8fc08085110de00ebcbd67b5273a755a5cb8ea1)
---
 src/callproc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/callproc.c b/src/callproc.c
index 4aa2463..fad8169 100644
--- a/src/callproc.c
+++ b/src/callproc.c
@@ -1602,7 +1602,9 @@ emacs_spawn (pid_t *newpid, int std_in, int std_out, int 
std_err,
 
   vfork_error = pid < 0 ? errno : 0;
 
+#if USABLE_POSIX_SPAWN
  fork_done:
+#endif
   if (pid < 0)
     {
       eassert (0 < vfork_error);