constify seq_file stuff

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index 0b69a46..44f1514 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -74,7 +74,7 @@
 	}
 }
 
-char *mangle_path(char *s, char *p, char *esc);
+char *mangle_path(char *s, const char *p, const char *esc);
 int seq_open(struct file *, const struct seq_operations *);
 ssize_t seq_read(struct file *, char __user *, size_t, loff_t *);
 loff_t seq_lseek(struct file *, loff_t, int);
@@ -86,10 +86,10 @@
 
 __printf(2, 3) int seq_printf(struct seq_file *, const char *, ...);
 
-int seq_path(struct seq_file *, struct path *, char *);
-int seq_dentry(struct seq_file *, struct dentry *, char *);
-int seq_path_root(struct seq_file *m, struct path *path, struct path *root,
-		  char *esc);
+int seq_path(struct seq_file *, const struct path *, const char *);
+int seq_dentry(struct seq_file *, struct dentry *, const char *);
+int seq_path_root(struct seq_file *m, const struct path *path,
+		  const struct path *root, const char *esc);
 int seq_bitmap(struct seq_file *m, const unsigned long *bits,
 				   unsigned int nr_bits);
 static inline int seq_cpumask(struct seq_file *m, const struct cpumask *mask)