drivers/misc/pti.c: give 'comm' function scope in pti_control_frame_built_and_sent()

In drivers/misc/pti.c::pti_control_frame_built_and_sent() we assign 'comm'
to 'thread_name_p' if (!thread_name).  The problem is that 'comm' then
goes out of scope and later we use 'thread_name_p' which now refers to an
out-of-scope variable.  To fix that, simply move 'comm' up to have
function scope.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: J Freyensee <james_p_freyensee@linux.intel.com>
Cc: Jeremy Rocher <rocher.jeremy@gmail.com>
Cc: Sergei Trofimovich <slyfox@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>