Clean up files that do not end with newlines

Trivial patch to add new lines to several files missing them. This fixes
warnings when compiling with gcc 4.1.2 on CentOS 5.

ASTERISK-24245 #close
Reported by: Shaun Ruffell
patches:
  0002-Trivial-addition-of-newlines-at-end-of-three-files.patch uploaded by Shaun Ruffell (License 5417)
........

Merged revisions 421677 from http://svn.asterisk.org/svn/asterisk/branches/12
........

Merged revisions 421678 from http://svn.asterisk.org/svn/asterisk/branches/13


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@421679 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/dns.c

@@ -339,4 +339,5 @@ struct ao2_container *ast_dns_get_nameservers(void)
 #endif
 
 	return nameservers;
-}
+}
+

main/format_cache.c

@@ -511,4 +511,5 @@ int ast_format_cache_is_slinear(struct ast_format *format)
 	}
 
 	return 0;
-}
+}
+

res/stasis/messaging.h

@@ -80,4 +80,4 @@ int messaging_cleanup(void);
  */
 int messaging_init(void);
 
-#endif /* #define _ASTERISK_RES_STASIS_MESSAGING_H  */
+#endif /* #define _ASTERISK_RES_STASIS_MESSAGING_H  */