pinctrl: thunderbay: fix possible memory leak in thunderbay_build_functions()

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

pinctrl: thunderbay: fix possible memory leak in thunderbay_build_functions()

The thunderbay_add_functions() will free memory of thunderbay_funcs

when everything is ok, but thunderbay_funcs will not be freed when

thunderbay_add_functions() fails, then there will be a memory leak,

so we need to add kfree() when thunderbay_add_functions() fails to

fix it.

In addition, doing some cleaner works, moving kfree(funcs) from

thunderbay_add_functions() to thunderbay_build_functions().