bpf: bpftool: Fix newline and p_err issue

This patch fixes a few newline issues and also
replaces p_err with p_info in prog.c

Fixes: b053b439 ("bpf: libbpf: bpftool: Print bpf_line_info during prog dump")
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>