cifs: properly handle case where CIFSGetSrvInodeNumber fails

...if it does then we pass a pointer to an unintialized variable for
the inode number to cifs_new_inode. Have it pass a NULL pointer instead.

Also tweak the function prototypes to reduce the amount of casting.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 62fd5bd..446e62c 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -92,8 +92,7 @@
 extern __le64 cnvrtDosCifsTm(__u16 date, __u16 time);
 extern struct timespec cnvrtDosUnixTm(__u16 date, __u16 time);
 
-extern struct inode *cifs_new_inode(struct super_block *sb,
-				    unsigned long *inum);
+extern struct inode *cifs_new_inode(struct super_block *sb, __u64 *inum);
 extern int cifs_get_inode_info(struct inode **pinode,
 			const unsigned char *search_path,
 			FILE_ALL_INFO *pfile_info,