Minimum viable patch to continue version autonegotiotion in
case where the server returns an unexpected NFS4ERR_INVAL,
which happens for a 4.0.4-303.fc22.x86_64 client talking to
a 2.6.35.14-106.fc14.i686.PAE server, see
https://bugzilla.redhat.com/show_bug.cgi?id=1228272

Signed-off-by: Anders Blomdell <anders.blomdell@control.lth.se>

--- utils/mount/stropts.c.orig	2015-06-18 09:51:02.091148891 +0200
+++ utils/mount/stropts.c	2015-06-18 09:48:56.859970023 +0200
@@ -838,6 +838,10 @@ check_result:
 		return result;
 
 	switch (errno) {
+	case EIO:
+		/* Fix to handle nfs4_discover_server_trunking returning
+		 * EIO in case where nfs server returns NFS4ERR_INVAL,
+		 * see https://bugzilla.redhat.com/show_bug.cgi?id=1228272 */
 	case EPROTONOSUPPORT:
 		/* A clear indication that the server or our
 		 * client does not support NFS version 4 and minor */