Add comment to AC_DEFINE_UNQUOTED use.

diff --git a/m4/glibc21.m4 b/m4/glibc21.m4
index dab37244da02789a2f272048a4249b9350df2bf7..03d9e44865543ef69e2f91f261110a63e49641b3 100644 (file)
--- a/m4/glibc21.m4
+++ b/m4/glibc21.m4
@@ -20,6 +20,7 @@ AC_DEFUN(jm_GLIBC21,
        ac_cv_gnu_library_2_1=no)
       ]
     )
-    AC_DEFINE_UNQUOTED(GLIBC21,$ac_cv_gnu_library_2_1)
+    AC_DEFINE_UNQUOTED(GLIBC21, $ac_cv_gnu_library_2_1,
+                       [we use GNU C Library 2.1 or newer])
   ]
 )