ata: pata_isapnp: Add missing error check for devm_ioport_map()

Add missing error return check for devm_ioport_map() and return the
error if this function call fails.

Fixes: 0d5ff566 ("libata: convert to iomap")
Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>