scsi: qla2xxx: Fix DMA mapping test in qla24xx_get_port_database()

scsi: qla2xxx: Fix DMA mapping test in qla24xx_get_port_database()

dma_map_XXX() functions return as error values DMA_MAPPING_ERROR which is
often ~0.  The error value should be tested with dma_mapping_error() like
it was done in qla26xx_dport_diagnostics().

Fixes: 818c7f87a177 ("scsi: qla2xxx: Add changes in preparation for vendor extended FDMI/RDP")
Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com>
Link: https://lore.kernel.org/r/20250617161115.39888-2-fourier.thomas@gmail.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>