Prima: Fix buffer overwrite problem in GETWESMODE

qcacld-2.0 to prima propagation

If (len + 1) is greater than priv_data.total_len then copy_to_user
results in writing more data than the buffer can hold.
Fix this by writing mininum of (len + 1) and priv_data.total_len.

Change-Id: I1ce46ee763dbd38a7e6a362d423a8038467ac503
CRs-Fixed: 865527
diff --git a/CORE/HDD/src/wlan_hdd_main.c b/CORE/HDD/src/wlan_hdd_main.c
index 989117b..a01f055 100755
--- a/CORE/HDD/src/wlan_hdd_main.c
+++ b/CORE/HDD/src/wlan_hdd_main.c
@@ -3479,8 +3479,8 @@
            tANI_U8 len = 0;
 
            len = scnprintf(extra, sizeof(extra), "%s %d", command, wesMode);
-           if (copy_to_user(priv_data.buf, &extra, len + 1))
-           {
+           len = VOS_MIN(priv_data.total_len, len + 1);
+           if (copy_to_user(priv_data.buf, &extra, len)) {
                VOS_TRACE( VOS_MODULE_ID_HDD, VOS_TRACE_LEVEL_ERROR,
                   "%s: failed to copy data to user buffer", __func__);
                ret = -EFAULT;