usb: ehci: replace scnprintf() with sysfs_emit()

Per Documentation/filesystems/sysfs.rst, show() methods should only
use sysfs_emit() or sysfs_emit_at() when formatting values to be
returned to userspace.

Convert the uses of scnprintf() in sysfs show() methods to
sysfs_emit() and sysfs_emit_at() for better safety and consistency.

Signed-off-by: Hendrik Hamerlinck <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/host/ehci-sysfs.c

···
 			      char *buf)
 {
 	struct ehci_hcd		*ehci;
-	int			nports, index, n;
-	int			count = PAGE_SIZE;
-	char			*ptr = buf;
+	int			nports, index;
+	int			len = 0;
 
 	ehci = hcd_to_ehci(dev_get_drvdata(dev));
 	nports = HCS_N_PORTS(ehci->hcs_params);
 
 	for (index = 0; index < nports; ++index) {
-		if (test_bit(index, &ehci->companion_ports)) {
-			n = scnprintf(ptr, count, "%d\n", index + 1);
-			ptr += n;
-			count -= n;
-		}
+		if (test_bit(index, &ehci->companion_ports))
+			len += sysfs_emit_at(buf, len, "%d\n", index + 1);
 	}
-	return ptr - buf;
+	return len;
 }
 
 /*
···
 					char *buf)
 {
 	struct ehci_hcd		*ehci;
-	int			n;
 
 	ehci = hcd_to_ehci(dev_get_drvdata(dev));
-	n = scnprintf(buf, PAGE_SIZE, "%d\n", ehci->uframe_periodic_max);
-	return n;
+	return sysfs_emit(buf, "%d\n", ehci->uframe_periodic_max);
 }