9p: missing chunk of "fs/9p: Don't update file type when updating file attributes"

In commit 45089142 Aneesh had missed one (admittedly, very unlikely
to hit) case in v9fs_stat2inode_dotl().  However, the same considerations
apply there as well - we have no business whatsoever to change ->i_rdev
or the file type.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/9p/vfs_inode_dotl.c

@@ -663,14 +663,10 @@ v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode,
 		if (stat->st_result_mask & P9_STATS_NLINK)
 			set_nlink(inode, stat->st_nlink);
 		if (stat->st_result_mask & P9_STATS_MODE) {
-			inode->i_mode = stat->st_mode;
-			if ((S_ISBLK(inode->i_mode)) ||
-						(S_ISCHR(inode->i_mode)))
-				init_special_inode(inode, inode->i_mode,
-								inode->i_rdev);
-		}
-		if (stat->st_result_mask & P9_STATS_RDEV)
-			inode->i_rdev = new_decode_dev(stat->st_rdev);
+			mode = stat->st_mode & S_IALLUGO;
+			mode |= inode->i_mode & ~S_IALLUGO;
+			inode->i_mode = mode;
+		}
 		if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE) &&
 		    stat->st_result_mask & P9_STATS_SIZE)
 			v9fs_i_size_write(inode, stat->st_size);