ext4: MMP: kmmpd should use nodename from init_uts_ns.name, not sysname

sysname holds "Linux" by default, i.e. what appears when doing a "uname
-s"; nodename should be used to print the machine's hostname, i.e. what
is returned when doing a "uname -n" or "hostname", and what
gethostname(2)/sethostname(2) manipulate, in order to notify the
administrator of the node which is contending to mount the filesystem.

Acked-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Nikitas Angelinas <nikitas_angelinas@xyratex.com>
Signed-off-by: Andrew Perepechko <andrew_perepechko@xyratex.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

fs/ext4/mmp.c

@@ -109,7 +109,7 @@ static int kmmpd(void *data)
 	mmp->mmp_check_interval = cpu_to_le16(mmp_check_interval);
 	bdevname(bh->b_bdev, mmp->mmp_bdevname);
 
-	memcpy(mmp->mmp_nodename, init_utsname()->sysname,
+	memcpy(mmp->mmp_nodename, init_utsname()->nodename,
 	       sizeof(mmp->mmp_nodename));
 
 	while (!kthread_should_stop()) {