[PATCH nft] datatype: display description for header field < 8 bits

[Pablo Neira Ayuso]

 # nft describe ip dscp
 payload expression, datatype dscp (Differentiated Services Code Point) 
(basetype integer), 6 bits

 pre-defined symbolic constants (in hexadecimal):
 nft: datatype.c:209: switch_byteorder: Assertion `len > 0' failed.
 Aborted

Fixes: c89a0801d077 ("datatype: Display pre-defined inet_service values in host 
byte order")
Signed-off-by: Pablo Neira Ayuso <pa...@netfilter.org>
---
 src/datatype.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/datatype.c b/src/datatype.c
index 873f7d4d358b..0ee2925a8368 100644
--- a/src/datatype.c
+++ b/src/datatype.c
@@ -220,6 +220,9 @@ void symbol_table_print(const struct symbol_table *tbl,
        unsigned int len = dtype->size / BITS_PER_BYTE;
        uint64_t value;
 
+       if (!len)
+               len = 1;
+
        for (s = tbl->symbols; s->identifier != NULL; s++) {
                value = s->value;
 
-- 
2.11.0