scripts: get_abi.pl: Ignore fs/cgroup sysfs nodes earlier

In order to speedup the parser and store less data, handle
fs/cgroup exceptions a lot earlier.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/caa37831c9e02ae58677d1515ed7cee94f52ea9d.1631957565.git.mchehab+huawei@kernel.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>