staging: octeon: check for pow0 before calling interface helper

Check for pow0 port first before calling the interface helper. This
avoids the following error log when setting up pow0 interface:

	cvmx_helper_get_interface_num: Illegal IPD port number
Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/octeon/ethernet-util.h

@@ -32,12 +32,13 @@ static inline void *cvm_oct_get_buffer_ptr(union cvmx_buf_ptr packet_ptr)
  */
 static inline int INTERFACE(int ipd_port)
 {
-	int interface = cvmx_helper_get_interface_num(ipd_port);
+	int interface;
 
+	if (ipd_port == CVMX_PIP_NUM_INPUT_PORTS)
+		return 10;
+	interface = cvmx_helper_get_interface_num(ipd_port);
 	if (interface >= 0)
 		return interface;
-	else if (ipd_port == CVMX_PIP_NUM_INPUT_PORTS)
-		return 10;
 	panic("Illegal ipd_port %d passed to INTERFACE\n", ipd_port);
 }