wlan: skipping the duplicate supported rates

If AP advertize the same rate in supported rates IE,
it will cross the max number of rates which is 12.
To fix it skipping the duplicate rates.

Change-Id: I5144ceba1b75cb7fdcfab0d8041e3e0020e900b0
CRs-Fixed: 889781
diff --git a/CORE/SME/src/csr/csrApiRoam.c b/CORE/SME/src/csr/csrApiRoam.c
index 5f89de3..45365da 100644
--- a/CORE/SME/src/csr/csrApiRoam.c
+++ b/CORE/SME/src/csr/csrApiRoam.c
@@ -3588,9 +3588,12 @@
             {
                 if ( csrRatesIsDot11RateSupported( pMac, pIes->SuppRates.rates[ i ] ) ) 
                 {
-                    csrAddRateBitmap(pIes->SuppRates.rates[ i ], &rateBitmap);
-                    *pDstRate++ = pIes->SuppRates.rates[ i ];
-                    pOpRateSet->numRates++;
+                    if ( !csrIsRateAlreadyPresent(pIes->SuppRates.rates[ i ], rateBitmap) )
+                    {
+                        csrAddRateBitmap(pIes->SuppRates.rates[ i ], &rateBitmap);
+                        *pDstRate++ = pIes->SuppRates.rates[ i ];
+                        pOpRateSet->numRates++;
+                    }
                 }
             }
         }