ubi: fix UBI_SILENCE_MSG

 - drop CONFIG_ prefix from kconfig entry
 - fix small compilation issue with CONFIG_UBI_SILENCE_MSG

Signed-off-by: Markus Klotzbuecher <markus.klotzbuecher@kistler.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Cc: Kyungmin Park <kmpark@infradead.org>
diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c
index 8ef7823..688fb50 100644
--- a/drivers/mtd/ubi/io.c
+++ b/drivers/mtd/ubi/io.c
@@ -1351,6 +1351,7 @@
 
 		ubi_err(ubi, "self-check failed for PEB %d:%d, len %d",
 			pnum, offset, len);
+#if !defined(CONFIG_UBI_SILENCE_MSG)
 		ubi_msg(ubi, "data differ at position %d", i);
 		ubi_msg(ubi, "hex dump of the original buffer from %d to %d",
 			i, i + dump_len);
@@ -1360,6 +1361,7 @@
 			i, i + dump_len);
 		print_hex_dump("", DUMP_PREFIX_OFFSET, 32, 1,
 			       buf1 + i, dump_len, 1);
+#endif
 		dump_stack();
 		err = -EINVAL;
 		goto out_free;