fix number of arguments to AC_DEFINE

aclocal hates when you only specify one parameter to AC_DEFINE ... simple patch
to add the other two parameters

fixes for acl and xfstests

[hch: added nfs4acl]

Reviewed-by: Christoph Hellwig <hch@lst.de>

m4/visibility_hidden.m4

@@ -17,6 +17,6 @@ EOF
 		  rm -f conftest.[cs]
 		  ])
    if test $libc_cv_visibility_attribute = yes; then
-     AC_DEFINE(HAVE_VISIBILITY_ATTRIBUTE)
+     AC_DEFINE(HAVE_VISIBILITY_ATTRIBUTE, [], [GCC supports visibility attributes])
    fi
   ])