[media] ir-lirc-codec.c: don't leak lirc->drv-rbuf

[media] ir-lirc-codec.c: don't leak lirc->drv-rbuf

As reported by kmemleak:

	unreferenced object 0xffff8802adae0ba0 (size 192):
	  comm "modprobe", pid 3024, jiffies 4296503588 (age 324.368s)
	  hex dump (first 32 bytes):
	    00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00  .....N..........
	    ff ff ff ff ff ff ff ff c0 48 25 a0 ff ff ff ff  .........H%.....
	  backtrace:
	    [<ffffffff82278c8e>] kmemleak_alloc+0x4e/0xb0
	    [<ffffffff8153c08c>] kmem_cache_alloc_trace+0x1ec/0x280
	    [<ffffffffa0250f0d>] ir_lirc_register+0x8d/0x7a0 [ir_lirc_codec]
	    [<ffffffffa07372b8>] ir_raw_event_register+0x318/0x4b0 [rc_core]
	    [<ffffffffa07351ed>] rc_register_device+0xf2d/0x1450 [rc_core]
	    [<ffffffffa13c5451>] au0828_rc_register+0x7d1/0xa10 [au0828]
	    [<ffffffffa13b0dc2>] au0828_usb_probe+0x6c2/0xcf0 [au0828]
	    [<ffffffff81d7619d>] usb_probe_interface+0x45d/0x940
	    [<ffffffff81ca7004>] driver_probe_device+0x454/0xd90
	    [<ffffffff81ca7a61>] __driver_attach+0x121/0x160
	    [<ffffffff81ca141f>] bus_for_each_dev+0x11f/0x1a0
	    [<ffffffff81ca5d4d>] driver_attach+0x3d/0x50
	    [<ffffffff81ca5039>] bus_add_driver+0x4c9/0x770
	    [<ffffffff81ca944c>] driver_register+0x18c/0x3b0
	    [<ffffffff81d71e58>] usb_register_driver+0x1f8/0x440
	    [<ffffffffa13680b7>] 0xffffffffa13680b7

	0xf3d is in ir_lirc_register (drivers/media/rc/ir-lirc-codec.c:348).
	343		drv = kzalloc(sizeof(struct lirc_driver), GFP_KERNEL);
	344		if (!drv)
	345			return rc;
	346
	347		rbuf = kzalloc(sizeof(struct lirc_buffer), GFP_KERNEL);
	348		if (!rbuf)
	349			goto rbuf_alloc_failed;
	350
	351		rc = lirc_buffer_init(rbuf, sizeof(int), LIRCBUF_SIZE);
	352		if (rc)

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>