bpf: Return -EFAULT on misconfigurations

Mark these cases as non-recoverable to later prevent them from being
caught when they occur during speculative path verification.

Eduard writes [1]:

  The only pace I'm aware of that might act upon specific error code
  from verifier syscall is libbpf. Looking through libbpf code, it seems
  that this change does not interfere with libbpf.

[1] https://lore.kernel.org/all/785b4531ce3b44a84059a4feb4ba458c68fce719.camel@gmail.com/



Signed-off-by: Luis Gerhorst <luis.gerhorst@fau.de>
Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: Henriette Herzog <henriette.herzog@rub.de>
Cc: Maximilian Ott <ott@cs.fau.de>
Cc: Milan Stephan <milan.stephan@fau.de>
Link: https://lore.kernel.org/r/20250603205800.334980-3-luis.gerhorst@fau.de


Signed-off-by: Alexei Starovoitov <ast@kernel.org>