Removed spurious includes.

src/names.c

@@ -20,9 +20,7 @@
 #include "system.h"
 
 #include <fnmatch.h>
-#include <grp.h>
 #include <hash.h>
-#include <pwd.h>
 #include <quotearg.h>
 
 #include "common.h"

src/xheader.c

@@ -18,9 +18,7 @@
 
 #include "system.h"
 
-#include <grp.h>
 #include <hash.h>
-#include <pwd.h>
 #include <quotearg.h>
 
 #include "common.h"