V4L/DVB: drivers/media/IR - improve keytable code

The attached patch rewrites much of the keytable code in
drivers/media/IR/ir-keytable.c.

The scancodes are now inserted into the array in sorted
order which allows for a binary search on lookup.

The code has also been shrunk by about 150 lines.

In addition it fixes the following bugs:

Any use of ir_seek_table() was racy.

ir_dev->driver_name is leaked between ir_input_register() and
ir_input_unregister().

ir_setkeycode() unconditionally does clear_bit() on dev->keybit
when removing a mapping, but there might be another mapping with
a different scancode and the same keycode.

This version has been updated to incorporate patch feedback from
Mauro Carvalho Chehab.

[mchehab@redhat.com: Fix a conflict with RC keytable breakup patches and input changes]
Signed-off-by: David Härdeman <david@hardeman.nu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

include/media/ir-core.h

@@ -47,7 +47,9 @@ struct ir_scancode {
 
 struct ir_scancode_table {
 	struct ir_scancode	*scan;
-	int			size;
+	unsigned int		size;	/* Max number of entries */
+	unsigned int		len;	/* Used number of entries */
+	unsigned int		alloc;	/* Size of *scan in bytes */
 	u64			ir_type;
 	char			*name;
 	spinlock_t		lock;