serial: sirf: fix endless loop bug in uart receive tasklet
serial: sirf: fix endless loop bug in uart receive tasklet

In special condition, when cpu schedule into rx_tmo_process_tl or
rx_dma_complete_tl and all the receive dma tasks have done, it will
go into endless loop because no dma task cookie status be changed.

Signed-off-by: Qipan Li <7edc63b2168f7aeebdbedbd3916b18244ee96ac4@csr.com>
Signed-off-by: Barry Song <a856445693a373abed3e477bd705f7011cbd8a1d@csr.com>
Signed-off-by: Greg Kroah-Hartman <4645f7897fd33786a2ee1264d590b3c400559d85@linuxfoundation.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs