proc_fops: convert drivers/isdn/ to seq_file

Convert code away from ->read_proc/->write_proc interfaces.  Switch to
proc_create()/proc_create_data() which make addition of proc entries
reliable wrt NULL ->proc_fops, NULL ->data and so on.

Problem with ->read_proc et al is described here commit
786d7e1612f0b0adb6046f19b906609e4fe8b1ba "Fix rmmod/read/write races in
/proc entries"

[akpm@linux-foundation.org: CONFIG_PROC_FS=n build fix]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: Karsten Keil <keil@b1-systems.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/isdn/capilli.h b/include/linux/isdn/capilli.h
index 7acb87a..d3e5e9d 100644
--- a/include/linux/isdn/capilli.h
+++ b/include/linux/isdn/capilli.h
@@ -50,8 +50,7 @@
 	u16  (*send_message)(struct capi_ctr *, struct sk_buff *skb);
 	
 	char *(*procinfo)(struct capi_ctr *);
-	int (*ctr_read_proc)(char *page, char **start, off_t off,
-			     int count, int *eof, struct capi_ctr *card);
+	const struct file_operations *proc_fops;
 
 	/* filled in before calling ready callback */
 	u8 manu[CAPI_MANUFACTURER_LEN];		/* CAPI_GET_MANUFACTURER */