configure: Avoid exit() when checking for __sync_sub_and_fetch()

Use of exit() requires a stdlib.h include. This check was failing for me
since the compiler defaulted to -Werror=implicit-function-declaration, so
__sync_sub_and_fetch() support was not dectected.

diff --git a/configure.ac b/configure.ac
index 60a4cbe119aeef3a048c594bdfb032d733bdc008..3b225a299632e4d10d0ad2fd1380c1adcb9d765c 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -625,7 +625,7 @@ AS_IF([test -n "$dbus_va_copy_func"],
 AC_CACHE_CHECK([whether $CC knows __sync_sub_and_fetch()],
   dbus_cv_sync_sub_and_fetch,
   [AC_LINK_IFELSE([
-     AC_LANG_PROGRAM([[]], [[int a = 4; int b = __sync_sub_and_fetch(&a, 4); exit(b); ]])],
+     AC_LANG_PROGRAM([[]], [[int a = 4; int b = __sync_sub_and_fetch(&a, 4); return b; ]])],
      [dbus_cv_sync_sub_and_fetch=yes],
      [dbus_cv_sync_sub_and_fetch=no])
   ])