Cast the NULL to a pointer type for 64 bit architectures

Submitted by:	harti
MFC after:	4 days

contrib/sendmail/smrsh/smrsh.c

@@ -9,6 +9,7 @@
  * forth in the LICENSE file which can be found at the top level of
  * the sendmail distribution.
  *
+ * $FreeBSD$
  */
 
 #include <sm/gen.h>
@@ -423,7 +424,8 @@ main(argc, argv)
 #ifdef DEBUG
 	(void) sm_io_fprintf(smioout, SM_TIME_DEFAULT, "%s\n", newcmdbuf);
 #endif /* DEBUG */
-	(void) execle("/bin/sh", "/bin/sh", "-c", newcmdbuf, NULL, newenv);
+	(void) execle("/bin/sh", "/bin/sh", "-c", newcmdbuf,
+		      (char *)NULL, newenv);
 	save_errno = errno;
 #ifndef DEBUG
 	syslog(LOG_CRIT, "Cannot exec /bin/sh: %s", sm_errstring(errno));