sparc: serial: sunhv: fix a double lock bug

sparc: serial: sunhv: fix a double lock bug

BugLink: http://bugs.launchpad.net/bugs/1643637
[ Upstream commit 344e3c7734d5090b148c19ac6539b8947fed6767 ]

We accidentally take the "port->lock" twice in a row.  This old code
was supposed to be deleted.

Fixes: e58e241c1788 ('sparc: serial: Clean up the locking for -rt')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>