src: use C99/POSIX types

"u_int" was a non-standardized extension predating C99 on some platforms.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
diff --git a/xtables.c b/xtables.c
index 2137c98..566b5c3 100644
--- a/xtables.c
+++ b/xtables.c
@@ -438,7 +438,7 @@
 	return -1;
 }
 
-u_int16_t xtables_parse_port(const char *port, const char *proto)
+uint16_t xtables_parse_port(const char *port, const char *proto)
 {
 	unsigned int portnum;
 
@@ -669,7 +669,7 @@
 	return ptr;
 }
 
-static int compatible_revision(const char *name, u_int8_t revision, int opt)
+static int compatible_revision(const char *name, uint8_t revision, int opt)
 {
 	struct xt_get_revision rev;
 	socklen_t s = sizeof(rev);
@@ -717,12 +717,12 @@
 }
 
 
-static int compatible_match_revision(const char *name, u_int8_t revision)
+static int compatible_match_revision(const char *name, uint8_t revision)
 {
 	return compatible_revision(name, revision, afinfo->so_rev_match);
 }
 
-static int compatible_target_revision(const char *name, u_int8_t revision)
+static int compatible_target_revision(const char *name, uint8_t revision)
 {
 	return compatible_revision(name, revision, afinfo->so_rev_target);
 }
@@ -1688,7 +1688,7 @@
 	{NULL},
 };
 
-u_int16_t
+uint16_t
 xtables_parse_protocol(const char *s)
 {
 	unsigned int proto;