mtd: Fix device name leak when register device failed in add_mtd_device()

In the Linux kernel, the following vulnerability has been resolved: mtd: Fix device name leak when register device failed in add_mtd_device() There is a kmemleak when register device failed: unreferenced object 0xffff888101aab550 (size 8): comm "insmod", pid 3922, jiffies 4295277753 (age 925.408s) hex dump (first 8 bytes): 6d 74 64 30 00 88 ff ff mtd0.... backtrace: [<00000000bde26724>] __kmalloc_node_track_caller+0x4e/0x150 [<000000003c32b416>] kvasprintf+0xb0/0x130 [<000000001f7a8f15>] kobject_set_name_vargs+0x2f/0xb0 [<000000006e781163>] dev_set_name+0xab/0xe0 [<00000000e30d0c78>] add_mtd_device+0x4bb/0x700 [<00000000f3d34de7>] mtd_device_parse_register+0x2ac/0x3f0 [<00000000c0d88488>] 0xffffffffa0238457 [<00000000b40d0922>] 0xffffffffa02a008f [<0000000023d17b9d>] do_one_initcall+0x87/0x2a0 [<00000000770f6ca6>] do_init_module+0xdf/0x320 [<000000007b6768fe>] load_module+0x2f98/0x3330 [<00000000346bed5a>] __do_sys_finit_module+0x113/0x1b0 [<00000000674c2290>] do_syscall_64+0x35/0x80 [<000000004c6a8d97>] entry_SYSCALL_64_after_hwframe+0x46/0xb0 If register device failed, should call put_device() to give up the reference.