errptrError format %s has arg pid of wrong type int

[rafaeldtinoco]

With the selftest PR in place:

#28

I got

$ make libbpfgo-static-test
make -C ./selftest/build
make[1]: Entering directory '/home/rafaeldtinoco/work/sources/ebpf/libbpfgo/selftest/build'
make -C /home/rafaeldtinoco/work/sources/ebpf/libbpfgo vmlinuxh
make[2]: Entering directory '/home/rafaeldtinoco/work/sources/ebpf/libbpfgo'
mkdir -p ./output
make[2]: Leaving directory '/home/rafaeldtinoco/work/sources/ebpf/libbpfgo'
clang -g -O2 -Wall -fpie -target bpf -I../../output -c libbpfgo_test.bpf.c -o libbpfgo_test.bpf.o
make[1]: Leaving directory '/home/rafaeldtinoco/work/sources/ebpf/libbpfgo/selftest/build'
CC=clang \
   CGO_CFLAGS="-I/home/rafaeldtinoco/work/sources/ebpf/libbpfgo/output" \
   CGO_LDFLAGS="-lelf -lz /home/rafaeldtinoco/work/sources/ebpf/libbpfgo/output/libbpf.a" \
   sudo -E go test .
# github.com/aquasecurity/libbpfgo
./libbpfgo.go:790:15: errptrError format %s has arg pid of wrong type int
./libbpfgo.go:802:14: Sprintf format %s has arg offset of wrong type uint32
FAIL	github.com/aquasecurity/libbpfgo [build failed]
FAIL
make: *** [Makefile:79: libbpfgo-static-test] Error 2

from go test. I believe:

10aa311

Fixes the issue

[rafaeldtinoco]

I think it can be merged in the same PR (#28).