Fix types-related warnings based on clang diagnostics

1. Fix some places where unsigned value compared < 0
2. Fix obsolete %Z specifier to more portable %z
3. Some erroneous types substitution
4. nl_msec2str() - 64-bit msec is now properly used,

Only safe changes. I mean int <--> uint32_t and signed/unsigned fixes.
Some functinos require size_t argument instead of int, but changes of
signatures of that functions is terrible thing.

Also, I do not pretend for a full list of fixes.
Just to shut up clang -Wall -Wextra

One more thing. ifindex. I don't change that because changes will
be too big for simple fix.

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/nl.c b/lib/nl.c
index b572a1a3..6b2f027b 100644
--- a/lib/nl.c
+++ b/lib/nl.c
@@ -417,7 +417,7 @@ errout:
 int nl_recv(struct nl_sock *sk, struct sockaddr_nl *nla,
 	    unsigned char **buf, struct ucred **creds)
 {
-	int n;
+	ssize_t n;
 	int flags = 0;
 	static int page_size = 0;
 	struct iovec iov;