get_kprobe_functions(): detect more non-attachable functions (#2077)
get_kprobe_functions(): detect more non-attachable functions (#2077)

* get_kprobe_functions(): detect more non-attachable functions

Improve get_kprobe_functions() to exclude more non-attachable functions
like IRQ routines and functions in kernel modules blacklisted via
NOKPROBE_SYMBOLS().

Signed-off-by: Andrea Righi <243bc7e273657b4ad9a7ca12a3b3ad7b5bb1c892@gmail.com>

* get_kprobe_functions: fix bytes/str type error

Signed-off-by: Andrea Righi <243bc7e273657b4ad9a7ca12a3b3ad7b5bb1c892@gmail.com>

mcaleavya/bcc,brendangregg/bcc,tuxology/bcc,brendangregg/bcc,iovisor/bcc,iovisor/bcc,tuxology/bcc,tuxology/bcc,brendangregg/bcc,iovisor/bcc,mcaleavya/bcc,mcaleavya/bcc,iovisor/bcc,tuxology/bcc,brendangregg/bcc,brendangregg/bcc,mcaleavya/bcc,mcaleavya/bcc,tuxology/bcc,iovisor/bcc