wlan: Roam Scan Channels buffer size changed

Currently SIR_ROAM_MAX_CHANNELS is defined as
NUM_RF_CHANNELS. But, NUM_RF_CHANNELS value is
tightly coupled with the nv bin file being used.
To make LFR related scan cache not to be coupled
with other features, the size of SIR_ROAM_MAX_CHANNELS
is defined to a constant value.

Change-Id: Id04d2bf9d75bc56fc2bd261ea593810c2b4e0981
CRs-Fixed: 606397
diff --git a/CORE/SME/src/csr/csrApiRoam.c b/CORE/SME/src/csr/csrApiRoam.c
index e14b9da..8585b38 100644
--- a/CORE/SME/src/csr/csrApiRoam.c
+++ b/CORE/SME/src/csr/csrApiRoam.c
@@ -15646,7 +15646,7 @@
    tSirBssDescription *pBssDesc = NULL;
    tDot11fBeaconIEs *pIes = NULL;
    tANI_U8 minRate = 0, dataRate;
-   tANI_U8 operationChannel;
+   tANI_U8 operationChannel = 0;
 
    currChannelListInfo = &pNeighborRoamInfo->roamChannelInfo.currentChannelListInfo;