Remove unused variable, fix signedness.

lib/zip_fclose.c

diff --git a/lib/zip_fclose.c b/lib/zip_fclose.c
index c336c31..00265cd 100644
--- a/lib/zip_fclose.c
+++ b/lib/zip_fclose.c
@@ -41,7 +41,6 @@
 zip_fclose(struct zip_file *zf)
 {
     int ret;
-    unsigned int i;
     
     if (zf->src)
 	zip_source_free(zf->src);

lib/zip_fopen_index_encrypted.c

diff --git a/lib/zip_fopen_index_encrypted.c b/lib/zip_fopen_index_encrypted.c
index 7aaf894..a640610 100644
--- a/lib/zip_fopen_index_encrypted.c
+++ b/lib/zip_fopen_index_encrypted.c
@@ -71,7 +71,7 @@
 static struct zip_file *
 _zip_file_new(struct zip *za)
 {
-    struct zip_file *zf, **file;
+    struct zip_file *zf;
 
     if ((zf=(struct zip_file *)malloc(sizeof(struct zip_file))) == NULL) {
 	_zip_error_set(&za->error, ZIP_ER_MEMORY, 0);

lib/zip_source_filep.c

diff --git a/lib/zip_source_filep.c b/lib/zip_source_filep.c
index 5c1a7ab..b05e960 100644
--- a/lib/zip_source_filep.c
+++ b/lib/zip_source_filep.c
@@ -295,7 +295,7 @@
 static void
 _zip_deregister_source(struct zip *za, void *ud)
 {
-    int i;
+    unsigned int i;
 
     for (i=0; i<za->nsource; i++) {
 	if (za->source[i]->ud == ud) {