Use setenv(), fix warnings

- Fix -Wundef -Wold-style-definition warnings
  - Make pll_free() static

[jc: original patch by Timo had another unrelated bits:

  - Use setenv() instead of putenv()

 I'm postponing that part for now.]

Signed-off-by: Timo Hirvonen <tihirvon@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>

cache.h

@@ -10,7 +10,7 @@
 #define deflateBound(c,s)  ((s) + (((s) + 7) >> 3) + (((s) + 63) >> 6) + 11)
 #endif
 
-#if defined(DT_UNKNOWN) && !NO_D_TYPE_IN_DIRENT
+#if defined(DT_UNKNOWN) && !defined(NO_D_TYPE_IN_DIRENT)
 #define DTYPE(de)	((de)->d_type)
 #else
 #undef DT_UNKNOWN

exec_cmd.c

@@ -13,7 +13,7 @@ void git_set_exec_path(const char *exec_path)
 
 
 /* Returns the highest-priority, location to look for git programs. */
-const char *git_exec_path()
+const char *git_exec_path(void)
 {
 	const char *env;
 

fetch-pack.c

@@ -82,7 +82,7 @@ static void mark_common(struct commit *commit,
   Get the next rev to send, ignoring the common.
 */
 
-static const unsigned char* get_rev()
+static const unsigned char* get_rev(void)
 {
 	struct commit *commit = NULL;
 

fsck-objects.c

@@ -20,7 +20,7 @@ static int check_strict = 0;
 static int keep_cache_objects = 0; 
 static unsigned char head_sha1[20];
 
-#if NO_D_INO_IN_DIRENT
+#ifdef NO_D_INO_IN_DIRENT
 #define SORT_DIRENT 0
 #define DIRENT_SORT_HINT(de) 0
 #else

pack-objects.c

@@ -768,7 +768,7 @@ static int sha1_sort(const struct object_entry *a, const struct object_entry *b)
 	return memcmp(a->sha1, b->sha1, 20);
 }
 
-static struct object_entry **create_final_object_list()
+static struct object_entry **create_final_object_list(void)
 {
 	struct object_entry **list;
 	int i, j;

pack-redundant.c

@@ -45,7 +45,7 @@ static inline void llist_item_put(struct llist_item *item)
 	free_nodes = item;
 }
 
-static inline struct llist_item *llist_item_get()
+static inline struct llist_item *llist_item_get(void)
 {
 	struct llist_item *new;
 	if ( free_nodes ) {
@@ -275,7 +275,7 @@ static void cmp_two_packs(struct pack_list *p1, struct pack_list *p2)
 	}
 }
 
-void pll_free(struct pll *l)
+static void pll_free(struct pll *l)
 {
 	struct pll *old;
 	struct pack_list *opl;