bpftool: Remove asserts from JIT disassembler

bpftool: Remove asserts from JIT disassembler

The JIT disassembler in bpftool is the only components (with the JSON
writer) using asserts to check the return values of functions. But it
does not do so in a consistent way, and diasm_print_insn() returns no
value, although sometimes the operation failed.

Remove the asserts, and instead check the return values, print messages
on errors, and propagate the error to the caller from prog.c.

Remove the inclusion of assert.h from jit_disasm.c, and also from map.c
where it is unused.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Tested-by: Niklas Söderlund <niklas.soderlund@corigine.com>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20221025150329.97371-3-quentin@isovalent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>