libudev: util - optimize path_encode()

Since we already know the length, use memcpy() instead.
Measured 2% _user_ cpu time reduction on EeePC coldplug.

Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>

udev/lib/libudev-util.c

@@ -114,7 +114,6 @@ size_t util_path_encode(char *s, size_t len)
 	char t[(len * 3)+1];
 	size_t i, j;
 
-	t[0] = '\0';
 	for (i = 0, j = 0; s[i] != '\0'; i++) {
 		if (s[i] == '/') {
 			memcpy(&t[j], "\\x2f", 4);
@@ -127,8 +126,11 @@ size_t util_path_encode(char *s, size_t len)
 			j++;
 		}
 	}
-	t[j] = '\0';
-	strncpy(s, t, len);
+	if (len == 0)
+		return j;
+	i = (j < len - 1) ? j : len - 1;
+	memcpy(s, t, i);
+	s[i] = '\0';
 	return j;
 }