fs: Quieten down the filesystems more

When looking for a filesystem on a partition we should do so quietly. At
present if the filesystem is very small (e.g. 512 bytes) we get a host of
messages.

Update these to only show when debugging.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/fs/fs_internal.c b/fs/fs_internal.c
index ae1cb85..111f91b 100644
--- a/fs/fs_internal.c
+++ b/fs/fs_internal.c
@@ -29,8 +29,7 @@
 	/* Check partition boundaries */
 	if ((sector + ((byte_offset + byte_len - 1) >> log2blksz))
 	    >= partition->size) {
-		log_err("%s read outside partition " LBAFU "\n", __func__,
-			sector);
+		log_debug("read outside partition " LBAFU "\n", sector);
 		return 0;
 	}