RDMA/uverbs: Allow the compiler to verify declaration and definition consistency

This patch avoids that sparse reports the following warnings:

drivers/infiniband/core/uverbs_std_types_flow_action.c:442:30: warning: symbol 'uverbs_def_obj_flow_action' was not declared. Should it be static?
drivers/infiniband/core/uverbs_std_types_dm.c:112:30: warning: symbol 'uverbs_def_obj_dm' was not declared. Should it be static?
drivers/infiniband/core/uverbs_std_types_counters.c:153:30: warning: symbol 'uverbs_def_obj_counters' was not declared. Should it be static?
drivers/infiniband/core/uverbs_std_types_mr.c:213:30: warning: symbol 'uverbs_def_obj_mr' was not declared. Should it be static?

Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Fixes: 0bd01f3d

 ("RDMA/uverbs: Require all objects to have a driver destroy function")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>