xprtrdma: fix incorrect header size calculations
Currently the header size calculations are using an assignment
operator instead of a += operator when accumulating the header
size leading to incorrect sizes. Fix this by using the correct
operator.
Addresses-Coverity: ("Unused value")
Fixes:
302d3deb2068 ("xprtrdma: Prevent inline overflow")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>