tifm_sd: use kmap_atomic instead of kmap for PIO data buffer

Data buffer for PIO transfer used to be mapped in advance with kmap.
Abolish it in favor of on-demand kmap_atomic.

Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
1 file changed