The main firmware messaging function returns the firmware defined error
code and many callers have to convert to standard error code for proper
propagation to userspace.  Convert bnxt_hwrm_do_send_msg() to return
standard error code so we can do away with all the special error code
handling by the many callers.
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>