Add inet_sockaddr2str() to wrap inet_ntop(3)

Signed-off-by: Alejandro Colomar <alx@kernel.org>

lib/prototypes.h

@@ -21,6 +21,7 @@
 
 #include <config.h>
 
+#include <sys/socket.h>
 #include <sys/stat.h>
 #include <utmp.h>
 #include <sys/types.h>
@@ -193,6 +194,9 @@ extern bool gr_append_member (struct group *grp, char *member);
 /* hushed.c */
 extern bool hushed (const char *username);
 
+/* inet_sockaddr2str.c */
+extern const char *inet_sockaddr2str(const struct sockaddr *sa);
+
 /* audit_help.c */
 #ifdef WITH_AUDIT
 extern int audit_fd;