staging: rtl8192u: use %*pEn to escape buffer

Let's use kernel's native specifier to escape a buffer.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: "John W . Linville" <linville@tuxdriver.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/staging/rtl8192u/ieee80211/ieee80211.h

@@ -2593,25 +2593,13 @@ static inline int ieee80211_get_scans(struct ieee80211_device *ieee)
 
 static inline const char *escape_essid(const char *essid, u8 essid_len) {
 	static char escaped[IW_ESSID_MAX_SIZE * 2 + 1];
-	const char *s = essid;
-	char *d = escaped;
 
 	if (ieee80211_is_empty_essid(essid, essid_len)) {
 		memcpy(escaped, "<hidden>", sizeof("<hidden>"));
 		return escaped;
 	}
 
-	essid_len = min(essid_len, (u8)IW_ESSID_MAX_SIZE);
-	while (essid_len--) {
-		if (*s == '\0') {
-			*d++ = '\\';
-			*d++ = '0';
-			s++;
-		} else {
-			*d++ = *s++;
-		}
-	}
-	*d = '\0';
+	snprintf(escaped, sizeof(escaped), "%*pEn", essid_len, essid);
 	return escaped;
 }