Slightly improve dumping packets

Add a function for dumping iovecs, and make hexdumps clearer by
adding spaces between bytes.

Bug: 8276725
Change-Id: Ifb2f8317613d05fa6bd600700090a6df258cde08
diff --git a/dump.h b/dump.h
index 6ca44bd..9cb040c 100644
--- a/dump.h
+++ b/dump.h
@@ -29,5 +29,6 @@
 void dump_tcp6(const struct tcphdr *tcp, const struct ip6_hdr *ip6, const char *payload, size_t payload_size, const char *options, size_t options_size);
 
 void logcat_hexdump(const char *info, const char *data, size_t len);
+void dump_iovec(const struct iovec *iov, int iov_len);
 
 #endif /* __DUMP_H__ */