BUG/MEDIUM: dns: don't store dns_build_query() result in the trash's length

By convenience or laziness we used to store dns_build_query()'s return code
into trash.data. The result checks applied there compare trash.data to -1
while it's now unsigned since commit 843b7cb ("MEDIUM: chunks: make the
chunk struct's fields match the buffer struct"). Let's clean this up
and test the result itself without storing it first.

No backport is needed.
1 file changed