stingray: fix coverity reported issues on brcm platform

fix coverity reported issues
1. uninitialized var,
2. check for negative val on unsigned variable

Signed-off-by: Sheetal Tigadoli <sheetal.tigadoli@broadcom.com>
Change-Id: I28b7517135ba6c1ba0df04f0c73189cf84ba89e6

plat/brcm/board/stingray/src/bl2_setup.c

@@ -682,7 +682,7 @@ void plat_bcm_bl2_plat_arch_setup(void)
 	bcm_board_detect();
 #ifdef DRIVER_EMMC_ENABLE
 	/* Initialize the card, if it is not */
-	if (bcm_emmc_init(true) < 0)
+	if (bcm_emmc_init(true) == 0)
 		WARN("eMMC Card Initialization Failed!!!\n");
 #endif
 

plat/brcm/board/stingray/src/paxb.c

@@ -485,7 +485,7 @@ static void pcie_ss_reset(void)
  */
 static int pcie_cores_init(void)
 {
-	int ret;
+	int ret = 0;
 	uint32_t core_idx;
 
 	if (paxb->pipemux_init) {