tools, bpf_asm: Exit non-zero on errors

... so callers can correctly detect failure.

Signed-off-by: Ian Denhardt <[e-mail]>
Signed-off-by: Daniel Borkmann <[e-mail]>
Link: https://lore.kernel.org/bpf/[e-mail]

tools/bpf/bpf_exp.y

···
 	| OP_LDXB number '*' '(' '[' number ']' '&' number ')' {
 		if ($2 != 4 || $9 != 0xf) {
 			fprintf(stderr, "ldxb offset not supported!\n");
-			exit(0);
+			exit(1);
 		} else {
 			bpf_set_curr_instr(BPF_LDX | BPF_MSH | BPF_B, 0, 0, $6); } }
 	| OP_LDX number '*' '(' '[' number ']' '&' number ')' {
 		if ($2 != 4 || $9 != 0xf) {
 			fprintf(stderr, "ldxb offset not supported!\n");
-			exit(0);
+			exit(1);
 		} else {
 			bpf_set_curr_instr(BPF_LDX | BPF_MSH | BPF_B, 0, 0, $6); } }
 	;
···
 {
 	if (curr_instr >= BPF_MAXINSNS) {
 		fprintf(stderr, "only max %u insns allowed!\n", BPF_MAXINSNS);
-		exit(0);
+		exit(1);
 	}
 }
 
···
 
 	if (ret == -ENOENT) {
 		fprintf(stderr, "no such label \'%s\'!\n", label);
-		exit(0);
+		exit(1);
 	}
 
 	return ret;