Remove redundant if()

Removed the redundant if() from the code snipit below:

// Wait for rvalid
if (mstr_mp.drv_mstr_cb.rvalid !== 1'b1) begin
    while (mstr_mp.drv_mstr_cb.rvalid !== 1'b1) begin
        @(mstr_mp.drv_mstr_cb);
    end
end

Signed-off-by: Mike Thompson mike@openhwgroup.org