hw/rdma: Switch to generic error reporting way

hw/rdma: Switch to generic error reporting way

Utilize error_report for all pr_err calls and some pr_dbg that are
considered as errors.
For the remaining pr_dbg calls, the important ones were replaced by
trace points while other deleted.
Some of the functions got renamed to include prefix "rdma/pvrdma"
in the function name.

Signed-off-by: Yuval Shaia <yuval.shaia@oracle.com>
Reviewed-by: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Message-Id: <1552300155-25216-2-git-send-email-yuval.shaia@oracle.com>
Reviewed-by: Kamal Heib <kamalheib1@gmail.com>
Signed-off-by: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>