socket: fix typo for default size

* ext/socket/ancdata.c (bsock_recvmsg_internal): use 4096 as
  default size to match pre-r52610, which also maps to a common
  page size.

Oops; absolutely no idea why I made this typo...

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52630 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,9 @@
+Wed Nov 18 10:12:36 2015  Eric Wong  <e@80x24.org>
+
+	* ext/socket/ancdata.c (bsock_recvmsg_internal): use 4096 as
+	  default size to match pre-r52610, which also maps to a common
+	  page size.
+
 Wed Nov 18 10:05:25 2015  Shugo Maeda  <shugo@ruby-lang.org>
 
 	* doc/syntax/refinements.rdoc: update documentation to reflect

ext/socket/ancdata.c

@@ -1465,7 +1465,7 @@ bsock_recvmsg_internal(VALUE sock,
     int gc_done = 0;
 #endif
 
-    maxdatlen = NIL_P(vmaxdatlen) ? 4061 : NUM2SIZET(vmaxdatlen);
+    maxdatlen = NIL_P(vmaxdatlen) ? 4096 : NUM2SIZET(vmaxdatlen);
 #if defined(HAVE_STRUCT_MSGHDR_MSG_CONTROL)
     maxctllen = NIL_P(vmaxctllen) ? 4096 : NUM2SIZET(vmaxctllen);
 #else