fix bad typing in defmt debug

Author: ValouBambou

src/fat/volume.rs

@@ -594,7 +594,7 @@ impl FatVolume {
                 debug!("LFN Contents {start} {sequence} {csum:02x} {buffer:04x?}");
                 #[cfg(feature = "defmt-log")]
                 debug!(
-                    "LFN Contents {=u8} {=u8} {=u8:02x} {=[?; 13]:#04x}",
+                    "LFN Contents {=bool} {=u8} {=u8:02x} {=[?; 13]:#04x}",
                     start, sequence, csum, buffer
                 );
                 match (start, sequence, self) {