iio: trigger: sysfs: fix possible memory leak in iio_sysfs_trig_init()

In the Linux kernel, the following vulnerability has been resolved:

iio: trigger: sysfs: fix possible memory leak in iio_sysfs_trig_init()

dev_set_name() allocates memory for name, it need be freed

when device_add() fails, call put_device() to give up the

reference that hold in device_initialize(), so that it can

be freed in kobject_cleanup() when the refcount hit to 0.

Fault injection test can trigger this:

unreferenced object 0xffff8e8340a7b4c0 (size 32):

comm "modprobe", pid 243, jiffies 4294678145 (age 48.845s)

hex dump (first 32 bytes):

69 69 6f 5f 73 79 73 66 73 5f 74 72 69 67 67 65 iio_sysfs_trigge

72 00 a7 40 83 8e ff ff 00 86 13 c4 f6 ee ff ff r..@............

backtrace:

[<0000000074999de8>] __kmem_cache_alloc_node+0x1e9/0x360

[<00000000497fd30b>] __kmalloc_node_track_caller+0x44/0x1a0

[<000000003636c520>] kstrdup+0x2d/0x60

[<0000000032f84da2>] kobject_set_name_vargs+0x1e/0x90

[<0000000092efe493>] dev_set_name+0x4e/0x70