Mute some warnings on uninitialized variables.

The code does the right thing, but the compiler is unable to figure it
out. All paths that use that variable use the same invariant.

usr.bin/passwd/passwd.c

@@ -67,7 +67,7 @@ int
 main(int argc, char *argv[])
 {
 	char hostname[MAXHOSTNAMELEN];
-	struct passwd *pwd;
+	struct passwd *pwd = NULL; /* Keep compiler happy. */
 	int o, pam_err;
 	uid_t uid;
 

usr.bin/sockstat/sockstat.c

@@ -496,8 +496,8 @@ printaddr(int af, struct sockaddr_storage *ss)
 {
 	char addrstr[INET6_ADDRSTRLEN] = { '\0', '\0' };
 	struct sockaddr_un *sun;
-	void *addr;
-	int off, port;
+	void *addr = NULL; /* Keep compiler happy. */
+	int off, port = 0;
 
 	switch (af) {
 	case AF_INET: