ANDROID: Avoid taking multiple locks in handle_lmk_event

Conflicting lock events have been reported resulting from
rcu_read_lock, mmap_sem (in get_cmdline) and  lmk_event_lock.

This CL avoids the possibility of these conditions by moving
handle_lmk_event outside rcu_read_lock and invoking get_cmdline before
lmk_event_lock is taken.

Bug: 133479338, 133829075
Signed-off-by: Jim Blackler <jimblackler@google.com>
Change-Id: I1c060dbd6200940d3b624ec275f31eedb5e2086d
Git-commit: c93a1fab248c46487da803590a0f1cec135cd96a
Git-repo: https://android.googlesource.com/kernel/common/


[spathi@codeaurora.org: resolved trivial merge conflicts]
Signed-off-by: Srinivasarao P <spathi@codeaurora.org>