qcacmn: Fix misspelling of "conversion"

The following change introduced a misspelling of "conversion", so fix
it.
- Change-Id I9f8fa776c65cbad84fac5e8c2f65b3fce1386e20
  qcacmn: update RSSI specific parameters in mon pdev

Change-Id: I019f929c09ad4e1de21ed9c7ac485a14f82d786c
CRs-Fixed: 3319342

qdf/inc/qdf_nbuf.h

@@ -368,7 +368,7 @@ typedef __qdf_nbuf_queue_t qdf_nbuf_queue_t;
  * @ht_crc: ht crc
  * @rx_user_status: pointer to mon_rx_user_status, when set update
  * @rssi_offset: This offset value will use for RSSI db to dbm conversion
- * @rssi_dbm_conv_support: Rssi dbm converstion support param
+ * @rssi_dbm_conv_support: Rssi dbm conversion support param
  * radiotap header will use userinfo from this structure.
  */
 struct mon_rx_status {