[process][darwin] Fix Parent() when lsof returns warnings

Same as #867, the error being:
error strconv.Atoi: parsing "      Output information may be incomplete.": invalid syntax

process/process_darwin.go

@@ -146,20 +146,18 @@ func (p *Process) createTimeWithContext(ctx context.Context) (int64, error) {
 }
 
 func (p *Process) ParentWithContext(ctx context.Context) (*Process, error) {
-	rr, err := common.CallLsofWithContext(ctx, invoke, p.Pid, "-FR")
+	out, err := common.CallLsofWithContext(ctx, invoke, p.Pid, "-FR")
 	if err != nil {
 		return nil, err
 	}
-	for _, r := range rr {
+	for _, line := range out {
-		if strings.HasPrefix(r, "p") { // skip if process
+		if len(line) >= 1 && line[0] == 'R' {
-			continue
+			v, err := strconv.Atoi(line[1:])
-		}
+			if err != nil {
-		l := string(r)
+				return nil, err
-		v, err := strconv.Atoi(strings.Replace(l, "R", "", 1))
+			}
-		if err != nil {
+			return NewProcessWithContext(ctx, int32(v))
-			return nil, err
 		}
-		return NewProcessWithContext(ctx, int32(v))
 	}
 	return nil, fmt.Errorf("could not find parent line")
 }

v3/process/process_darwin.go

@@ -146,20 +146,18 @@ func (p *Process) createTimeWithContext(ctx context.Context) (int64, error) {
 }
 
 func (p *Process) ParentWithContext(ctx context.Context) (*Process, error) {
-	rr, err := common.CallLsofWithContext(ctx, invoke, p.Pid, "-FR")
+	out, err := common.CallLsofWithContext(ctx, invoke, p.Pid, "-FR")
 	if err != nil {
 		return nil, err
 	}
-	for _, r := range rr {
+	for _, line := range out {
-		if strings.HasPrefix(r, "p") { // skip if process
+		if len(line) >= 1 && line[0] == 'R' {
-			continue
+			v, err := strconv.Atoi(line[1:])
-		}
+			if err != nil {
-		l := string(r)
+				return nil, err
-		v, err := strconv.Atoi(strings.Replace(l, "R", "", 1))
+			}
-		if err != nil {
+			return NewProcessWithContext(ctx, int32(v))
-			return nil, err
 		}
-		return NewProcessWithContext(ctx, int32(v))
 	}
 	return nil, fmt.Errorf("could not find parent line")
 }