bcachefs: Fix bch2_prt_bitflags()

This fixes an infinite loop when there's a set bit at position >= 32.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/printbuf.c

@@ -415,11 +415,11 @@ void bch2_prt_bitflags(struct printbuf *out,
 	while (list[nr])
 		nr++;
 
-	while (flags && (bit = __ffs(flags)) < nr) {
+	while (flags && (bit = __ffs64(flags)) < nr) {
 		if (!first)
 			bch2_prt_printf(out, ",");
 		first = false;
 		bch2_prt_printf(out, "%s", list[bit]);
-		flags ^= 1 << bit;
+		flags ^= BIT_ULL(bit);
 	}
 }