cifs: use type __u32 instead of int for the oplock parameter

... and avoid implicit casting from a signed type. Also, pass oplock by value
instead by reference as we don't intend to change the value in
cifs_open_inode_helper().

Thanks to Jeff Layton for spotting this.
Reviewed-by: Jeff Layton <jlayton@samba.org>
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/file.c

@@ -165,7 +165,7 @@ cifs_posix_open_inode_helper(struct inode *inode, struct file *file,
 
 /* all arguments to this function must be checked for validity in caller */
 static inline int cifs_open_inode_helper(struct inode *inode,
-	struct cifsTconInfo *pTcon, int *oplock, FILE_ALL_INFO *buf,
+	struct cifsTconInfo *pTcon, __u32 oplock, FILE_ALL_INFO *buf,
 	char *full_path, int xid)
 {
 	struct cifsInodeInfo *pCifsInode = CIFS_I(inode);
@@ -207,11 +207,11 @@ static inline int cifs_open_inode_helper(struct inode *inode,
 		rc = cifs_get_inode_info(&inode, full_path, buf, inode->i_sb,
 					 xid, NULL);
 
-	if ((*oplock & 0xF) == OPLOCK_EXCLUSIVE) {
+	if ((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
 		pCifsInode->clientCanCacheAll = true;
 		pCifsInode->clientCanCacheRead = true;
 		cFYI(1, "Exclusive Oplock granted on inode %p", inode);
-	} else if ((*oplock & 0xF) == OPLOCK_READ)
+	} else if ((oplock & 0xF) == OPLOCK_READ)
 		pCifsInode->clientCanCacheRead = true;
 
 	return rc;
@@ -365,7 +365,7 @@ int cifs_open(struct inode *inode, struct file *file)
 		goto out;
 	}
 
-	rc = cifs_open_inode_helper(inode, tcon, &oplock, buf, full_path, xid);
+	rc = cifs_open_inode_helper(inode, tcon, oplock, buf, full_path, xid);
 	if (rc != 0)
 		goto out;