zram: use __sysfs_match_string() helper

Use __sysfs_match_string() helper instead of open coded variant.

Link: http://lkml.kernel.org/r/20170609120835.22156-1-andriy.shevchenko@linux.intel.comSigned-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: NMinchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/block/zram/zcomp.c

@@ -68,13 +68,11 @@ static struct zcomp_strm *zcomp_strm_alloc(struct zcomp *comp)
 
 bool zcomp_available_algorithm(const char *comp)
 {
-	int i = 0;
+	int i;
 
-	while (backends[i]) {
-		if (sysfs_streq(comp, backends[i]))
-			return true;
-		i++;
-	}
+	i = __sysfs_match_string(backends, -1, comp);
+	if (i >= 0)
+		return true;
 
 	/*
 	 * Crypto does not ignore a trailing new line symbol,