Restore CFLAGS after checking for __attribute__
diff --git a/configure.in b/configure.in
index 4ab84dd..41c0eb5 100644
--- a/configure.in
+++ b/configure.in
@@ -903,6 +903,7 @@
   AC_MSG_RESULT(yes),
   AC_MSG_RESULT(no)
   )
+  CFLAGS=$save_CFLAGS
 fi
 
 # On some compilers, pthreads are available without further options