qcacld-3.0: Fix uninitialized variable use in wma_get_mcs_idx

In function wma_get_mcs_idx variable "match_rate"  is not initialized.
Initialize "match_rate" to avoid dereferencing uninitialized variable.

Change-Id: Id4c7e1913628007087c58149e4b7033320d4cc79
CRs-Fixed: 1042968

core/wma/src/wma_utils.c

@@ -205,7 +205,7 @@ static uint8_t wma_get_mcs_idx(uint16_t maxRate, uint8_t rate_flags,
 			       uint8_t nss, uint8_t *mcsRateFlag)
 {
 	uint8_t  index = 0;
-	uint16_t match_rate;
+	uint16_t match_rate = 0;
 	bool is_sgi = false;
 
 	WMA_LOGD("%s rate:%d rate_flgs: 0x%x, nss: %d",