block: zram: Default to LZ4 if support is enabled

Actually this has been applied with the different way using this 91f471c but reseted 6c58d3d.
So, let's follow Albert rules :p

Change-Id: Iefdf65011a7f25470c97d6dd5f094acb30b4e419
Signed-off-by: Albert I <krascgq@outlook.co.id>
Signed-off-by: khusika <khusikadhamar@gmail.com>

drivers/block/zram/zram_drv.c

@@ -40,7 +40,13 @@ static DEFINE_IDR(zram_index_idr);
 static DEFINE_MUTEX(zram_index_mutex);
 
 static int zram_major;
-static const char *default_compressor = "lzo";
+static const char *default_compressor = 
+#ifdef CONFIG_ZRAM_LZ4_COMPRESS
+"lz4"
+#else
+"lzo"
+#endif
+;
 
 /*
  * We don't need to see memory allocation errors more than once every 1