cifs: add parens around smb_var in BCC macros

...to remove ambiguity about how these values are interpreted when
passing in more complex values as arguments.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/cifspdu.h

@@ -415,10 +415,10 @@ struct smb_hdr {
 	__u8 WordCount;
 } __attribute__((packed));
 /* given a pointer to an smb_hdr retrieve the value of byte count */
-#define BCC(smb_var) (*(__u16 *)((char *)smb_var + sizeof(struct smb_hdr) + (2 * smb_var->WordCount)))
-#define BCC_LE(smb_var) (*(__le16 *)((char *)smb_var + sizeof(struct smb_hdr) + (2 * smb_var->WordCount)))
+#define BCC(smb_var) (*(__u16 *)((char *)(smb_var) + sizeof(struct smb_hdr) + (2 * (smb_var)->WordCount)))
+#define BCC_LE(smb_var) (*(__le16 *)((char *)(smb_var) + sizeof(struct smb_hdr) + (2 * (smb_var)->WordCount)))
 /* given a pointer to an smb_hdr retrieve the pointer to the byte area */
-#define pByteArea(smb_var) ((unsigned char *)smb_var + sizeof(struct smb_hdr) + (2 * smb_var->WordCount) + 2)
+#define pByteArea(smb_var) ((unsigned char *)(smb_var) + sizeof(struct smb_hdr) + (2 * (smb_var)->WordCount) + 2)
 
 /*
  * Computer Name Length (since Netbios name was length 16 with last byte 0x20)