procd: Set /dev/kmsg to 600

Small cleanup. I initially though /dev/kmsg was used for dmsg(and journald
on desktops) but this seems not to be the case. dmsg is still accessible
as non-root(gives output) which begs the question what does this do? Some
googling reveals that permissions are set to 600 for some embedded systems
while 644 for others. I can't find any justification for the latter. Might
as well err on the side of caution.

Signed-off by: Rosen Penev <rosenp@gmail.com>

package/system/procd/files/hotplug.json

@@ -16,10 +16,6 @@
 							[ "return" ],
 						]
 					],
-					[ "if",
-						[ "eq", "DEVNAME", "kmsg" ],
-						[ "makedev", "/dev/%DEVNAME%", "0644" ],
-					],
 					[ "if",
 						[ "regex", "DEVNAME", "^snd" ],
 						[ "makedev", "/dev/%DEVNAME%", "0660", "audio" ],