RDMa/uverbs: Copy ex_hdr outside of SRCU read lock

The SRCU read lock protects the IB device pointer
and doesn't need to be called before copying user
provided header.

Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
1 file changed