staging: logger: hold mutex while removing reader

The readers list is traversed under the log->mutex lock
(for example from fix_up_readers()), but the deletion of
elements from this list is not being done under this lock.

Cc: Brian Swetland <swetland@google.com>
Cc: Dima Zavin <dima@android.com>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cpufreq: interactive: sync android-3.0 with android-3.4

Change-Id: I71443db4edbe43a08fe58a54a742b4c788ef11e3
Signed-off-by: Todd Poynor <toddpoynor@google.com>
ancora: Update defconfig