examples: Resolve sign-compare warnings

For instance:

hellolibvirt/hellolibvirt.c: In function 'showDomains':
hellolibvirt/hellolibvirt.c:100:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (i = 0; i < numNames; i++) {
                   ^
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

examples/admin/client_info.c

@@ -102,7 +102,7 @@ int main(int argc, char **argv)
     virAdmClientPtr clnt = NULL;   /* which client get identity for */
     virTypedParameterPtr params = NULL;     /* where to store identity info */
     int nparams = 0;
-    size_t i = 0;
+    ssize_t i = 0;
     char *timestr = NULL;
 
     if (argc != 3) {

examples/admin/client_limits.c

@@ -9,7 +9,7 @@ int main(int argc, char **argv)
     virAdmServerPtr srv = NULL;     /* which server to work with */
     virTypedParameterPtr params = NULL;
     int nparams = 0;
-    size_t i;
+    ssize_t i;
 
     if (argc != 2) {
         fprintf(stderr, "One argument specifying the server which to work "

examples/admin/list_clients.c

@@ -50,7 +50,7 @@ int main(int argc, char **argv)
     virAdmConnectPtr conn = NULL;
     virAdmServerPtr srv = NULL;      /* which server list the clients from */
     virAdmClientPtr *clients = NULL;    /* where to store the servers */
-    size_t i = 0;
+    ssize_t i = 0;
     int count = 0;
 
     if (argc != 2) {

examples/admin/list_servers.c

@@ -8,7 +8,7 @@ int main(void)
     virAdmConnectPtr conn = NULL;
     virAdmServerPtr *servers = NULL;    /* where to store the servers */
     virAdmServerPtr *tmp = NULL;
-    size_t i = 0;
+    ssize_t i = 0;
     int count = 0;
 
     /* first, open a connection to the daemon */

examples/admin/threadpool_params.c

@@ -9,7 +9,7 @@ int main(int argc, char **argv)
     virAdmServerPtr srv = NULL;     /* which server to work with */
     virTypedParameterPtr params = NULL;
     int nparams = 0;
-    size_t i;
+    ssize_t i;
 
     if (argc != 2) {
         fprintf(stderr, "One argument specifying the server which to work "

examples/domsuspend/suspend.c

@@ -156,7 +156,7 @@ fetch_domains(virConnectPtr conn)
 {
     int num_domains, ret = -1;
     virDomainPtr *domains = NULL;
-    size_t i;
+    ssize_t i;
     const int list_flags = VIR_CONNECT_LIST_DOMAINS_ACTIVE;
 
     DEBUG("Fetching list of running domains");

examples/domtop/domtop.c

@@ -161,7 +161,7 @@ fetch_domains(virConnectPtr conn)
 {
     int num_domains, ret = -1;
     virDomainPtr *domains = NULL;
-    size_t i;
+    ssize_t i;
     const int list_flags = VIR_CONNECT_LIST_DOMAINS_ACTIVE;
 
     DEBUG("Fetching list of running domains");

examples/hellolibvirt/hellolibvirt.c

@@ -55,7 +55,7 @@ static int
 showDomains(virConnectPtr conn)
 {
     int ret = 0, numNames, numInactiveDomains, numActiveDomains;
-    size_t i;
+    ssize_t i;
     int flags = VIR_CONNECT_LIST_DOMAINS_ACTIVE |
                 VIR_CONNECT_LIST_DOMAINS_INACTIVE;
     virDomainPtr *nameList = NULL;

examples/openauth/openauth.c

@@ -91,7 +91,7 @@ static int
 showDomains(virConnectPtr conn)
 {
     int ret = 0, numNames, numInactiveDomains, numActiveDomains;
-    size_t i;
+    ssize_t i;
     char **nameList = NULL;
 
     numActiveDomains = virConnectNumOfDomains(conn);