iommu: Suppress empty whitespaces in prints

If IOMMU_CMD_LINE_DMA_API or IOMMU_CMD_LINE_STRICT are not set in
iommu_cmd_line, we will be emitting a whitespace before the newline.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230509191049.1752259-1-f.fainelli@gmail.com


Signed-off-by: Joerg Roedel <jroedel@suse.de>