Use strings.Cut in getNprocsProcStat

Also make the skip condition on the first line explicit.

sysconf_linux.go

@@ -86,10 +86,16 @@ func getNprocsProcStat() (int64, error) {
 	s := bufio.NewScanner(f)
 	for s.Scan() {
 		if line := strings.TrimSpace(s.Text()); strings.HasPrefix(line, "cpu") {
-			l := strings.SplitN(line, " ", 2)
-			_, err := strconv.ParseInt(l[0][3:], 10, 64)
-			if err == nil {
-				count++
+			cpu, _, found := strings.Cut(line, " ")
+			if found {
+				// skip first line with accumulated values
+				if cpu == "cpu" {
+					continue
+				}
+				_, err := strconv.ParseInt(cpu[len("cpu"):], 10, 64)
+				if err == nil {
+					count++
+				}
 			}
 		} else {
 			// The current format of /proc/stat has all the