i40e/i40evf: fix I40E_MASK signed shift overflow warnings

GCC 6 has a new warning which will display when you attempt to left
shift a signed value beyond the storage size of the type. I40E_MASK
generates a mask value for 32bit registers. Properly typecast the mask
value and place the values in parenthesis to prevent macro expansion
issues.
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e_type.h

@@ -36,7 +36,7 @@
 #include "i40e_devids.h"
 
 /* I40E_MASK is a macro used on 32 bit registers */
-#define I40E_MASK(mask, shift) (mask << shift)
+#define I40E_MASK(mask, shift) ((u32)(mask) << (shift))
 
 #define I40E_MAX_VSI_QP			16
 #define I40E_MAX_VF_VSI			3

drivers/net/ethernet/intel/i40evf/i40e_type.h

@@ -36,7 +36,7 @@
 #include "i40e_devids.h"
 
 /* I40E_MASK is a macro used on 32 bit registers */
-#define I40E_MASK(mask, shift) (mask << shift)
+#define I40E_MASK(mask, shift) ((u32)(mask) << (shift))
 
 #define I40E_MAX_VSI_QP			16
 #define I40E_MAX_VF_VSI			3