Prefer using ftrace over function entry/exit logging messages.

Warn with various function entry/exit only logging that only
use __func__ with or without descriptive decoration.

Link: https://lkml.kernel.org/r/47c01081533a417c99c9a80a4cd537f8c308503f.camel@perches.comSigned-off-by: NJoe Perches <joe@perches.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>