tty/serial: atmel: remove redundant assignment to ret

Variable ret is initialized to a value that is never read and it
is re-assigned later. The initialization is redundant and can be
removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20190809174042.6276-1-colin.king@canonical.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>