nvmem: core: Fix memleak in nvmem_register()

In the Linux kernel, the following vulnerability has been resolved: nvmem: core: Fix memleak in nvmem_register() dev_set_name will alloc memory for nvmem->dev.kobj.name in nvmem_register, when nvmem_validate_keepouts failed, nvmem's memory will be freed and return, but nobody will free memory for nvmem->dev.kobj.name, there will be memleak, so moving nvmem_validate_keepouts() after device_register() and let the device core deal with cleaning name in error cases.