serial: sprd: correct the wrong sequence of arguments

The sequence of arguments which was passed to handle_lsr_errors() didn't
match the parameters defined in that function, &lsr was passed to flag
and &flag was passed to lsr, this patch fixed that.

Fixes: b7396a38

 ("tty/serial: Add Spreadtrum sc9836-uart driver support")
Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
Signed-off-by: Chunyan Zhang <zhang.lyra@gmail.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20190905074151.5268-1-zhang.lyra@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>