tools: bpftool: move p_err() and p_info() from main.h to common.c

The two functions were declared as static inline in a header file. There
is no particular reason why they should be inlined, they just happened to
remain in the same header file when they were turned from macros to
functions in a precious commit.

Make them non-inlined functions and move them to common.c file instead.

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>