sqfs: Suppress the message about missing filesystem

This message comes up a lot when scanning filesystems. It suggests to the
user that there is some sort of error, but in fact there is no reason to
expect that a particular partition has a sqfs filesystem. Other
filesystems don't print this error.

Turn it into a debug message.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
diff --git a/fs/squashfs/sqfs.c b/fs/squashfs/sqfs.c
index 92ab8ac..e2d91c6 100644
--- a/fs/squashfs/sqfs.c
+++ b/fs/squashfs/sqfs.c
@@ -1090,7 +1090,7 @@
 
 	/* Make sure it has a valid SquashFS magic number*/
 	if (get_unaligned_le32(&sblk->s_magic) != SQFS_MAGIC_NUMBER) {
-		printf("Bad magic number for SquashFS image.\n");
+		debug("Bad magic number for SquashFS image.\n");
 		ret = -EINVAL;
 		goto error;
 	}