s390 has overlapping address space for user and kernel. Hence separation of
bpf_probe_read_user and bpf_probe_read_kernel is essential. Commit 6ae08ae3dea2
("bpf: Add probe_read_{user, kernel} and probe_read_{user, kernel}_str
helpers") introduced these changes into the kernel. However, bcc tools does not
respect it.

As a workaround, perform the following:
1. Use bpf_probe_read_user() explicitly in the bcc tools.
2. When kernel version < 5.5, perform the checks if the
   bpf_probe_read_user kernel helper is present in the backported kernel
   as well. If not found, then fallback from bpf_probe_read_user to
   bpf_probe_read.

Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>