libopenbmc_intf: fix various warnings

Trying to compile with stricter warnings results in numerous
errors, such as ignored results and unsigned/signed comparisons.
Fix these in libopenbmc_intf.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ia0b34fdc27b32675082741a0f3c18f0b538be108
diff --git a/libopenbmc_intf/gpio_configs.c b/libopenbmc_intf/gpio_configs.c
index 93203c1..3cd56cb 100644
--- a/libopenbmc_intf/gpio_configs.c
+++ b/libopenbmc_intf/gpio_configs.c
@@ -95,7 +95,7 @@
 			g_assert(polarity != NULL);
 			gpios->power_gpio.power_up_pols[i] = polarity->valueint;
 
-			g_print("Power GPIO power_up[%d] = %s active %s\n",
+			g_print("Power GPIO power_up[%zd] = %s active %s\n",
 					i, gpios->power_gpio.power_up_outs[i].name,
 					gpios->power_gpio.power_up_pols[i] ? "HIGH" : "LOW");
 			i++;
@@ -129,7 +129,7 @@
 			g_assert(polarity != NULL);
 			gpios->power_gpio.reset_pols[i] = polarity->valueint;
 
-			g_print("Power GPIO reset[%d] = %s active %s\n", i,
+			g_print("Power GPIO reset[%zd] = %s active %s\n", i,
 					gpios->power_gpio.reset_outs[i].name,
 					gpios->power_gpio.reset_pols[i] ? "HIGH" : "LOW");
 			i++;
@@ -174,7 +174,7 @@
 			g_assert(hold != NULL);
 			gpios->power_gpio.pci_reset_holds[i] = polarity->valueint;
 
-			g_print("Power GPIO pci reset[%d] = %s active %s, hold %s\n", i,
+			g_print("Power GPIO pci reset[%zd] = %s active %s, hold %s\n", i,
 					gpios->power_gpio.pci_reset_outs[i].name,
 					gpios->power_gpio.pci_reset_pols[i] ? "HIGH" : "LOW",
 					gpios->power_gpio.pci_reset_holds[i] ? "Yes" : "No");
@@ -201,7 +201,7 @@
 }
 
 void free_gpios(GpioConfigs *gpios) {
-	int i;
+	size_t i;
 	g_free(gpios->power_gpio.latch_out.name);
 	g_free(gpios->power_gpio.power_good_in.name);
 	for(i = 0; i < gpios->power_gpio.num_power_up_outs; i++) {