IB/hfi1: Relocate rcvhdrcnt module parameter check.

Validate the rcvhdrcnt module parameter in a single function at module
load time. This allows proper error reporting.

Reviewed-by: Dean Luick <dean.luick@intel.com>
Signed-off-by: Krzysztof Blaszkowski <krzysztof.blaszkowski@intel.com>
Signed-off-by: Tymoteusz Kielan <tymoteusz.kielan@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>