serial: sh-sci: simplify locking when re-issuing RXDMA fails

Avoid a superfluous unlock/lock-pair by simply moving the printout to
the end of bailing out.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20240506114016.30498-10-wsa+renesas@sang-engineering.com


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