ftrace: Remove redundant strsep in mod_callback
ftrace: Remove redundant strsep in mod_callback

By now there isn't any subcommand for mod.

Before:
	sh$ echo '*:mod:ipv6:a' > set_ftrace_filter
	sh$ echo '*:mod:ipv6' > set_ftrace_filter
had the same results, but now first will result in:
	sh$ echo '*:mod:ipv6:a' > set_ftrace_filter
	-bash: echo: write error: Invalid argument

Also, I clarified ftrace_mod_callback code a little.

Link: http://lkml.kernel.org/r/1443545176-3215-1-git-send-email-395d9bb87d8fb3640a03a9e24bd55fe3dab2053e@gmail.com

Signed-off-by: Dmitry Safonov <395d9bb87d8fb3640a03a9e24bd55fe3dab2053e@gmail.com>
[ converted 'if (ret == 0)' to 'if (!ret)' ]
Signed-off-by: Steven Rostedt <43232e92d70cc7aa53504ad0397085ee47bad87f@goodmis.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs