RDMA/pvrdma: Use non-atomic bitmap functions when possible

RDMA/pvrdma: Use non-atomic bitmap functions when possible

In 'pvrdma_uar_table_init()', the 'tbl->table' bitmap has just been
allocated, so no concurrent accesses can occur.

The other accesses to the 'tbl->table' bitmap are protected by the
'tbl->lock' spinlock, so no concurrent accesses can happen.

So prefer the non-atomic '__[set|clear]_bit()' functions to save a few
cycles.

Link: https://lore.kernel.org/r/271b0e2c316e2b4cf34ac6fbca0701edd2d882ec.1637870667.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>