tools, bpf_asm: Exit non-zero on errors

... so callers can correctly detect failure.
Signed-off-by: Ian Denhardt <ian@zenhack.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/b0bea780bc292f29e7b389dd062f20adc2a2d634.1614201868.git.ian@zenhack.net

tools/bpf/bpf_exp.y

@@ -185,13 +185,13 @@ ldx
 	| 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); } }
 	;
@@ -472,7 +472,7 @@ static void bpf_assert_max(void)
 {
 	if (curr_instr >= BPF_MAXINSNS) {
 		fprintf(stderr, "only max %u insns allowed!\n", BPF_MAXINSNS);
-		exit(0);
+		exit(1);
 	}
 }
 
@@ -522,7 +522,7 @@ static int bpf_find_insns_offset(const char *label)
 
 	if (ret == -ENOENT) {
 		fprintf(stderr, "no such label \'%s\'!\n", label);
-		exit(0);
+		exit(1);
 	}
 
 	return ret;