RDMA/efa: Use strscpy instead of strlcpy

The strlcpy function doesn't limit the source length, use the preferred
strscpy function instead.

Link: https://lore.kernel.org/r/20210329120131.18793-1-galpress@amazon.com


Reviewed-by: Firas JahJah <firasj@amazon.com>
Reviewed-by: Yossi Leybovich <sleybo@amazon.com>
Signed-off-by: Gal Pressman <galpress@amazon.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>