qcacmn: Fix use-after-freed when sending WMI command to FW

Using a buffer after passing it to wmi_unified_cmd_send() induces a
race condition that may result in a use-after-freed situation. Fix
several potential use-after-freed situations when calling
wmi_unified_cmd_send() by ensuring all access to a buffer is done
before the call to wmi_unified_cmd_send().

Change-Id: I985aad6e49daf1d823e3751a9cb0a293a298323c
CRs-Fixed: 1089713

wmi_unified.c

@@ -1738,6 +1738,8 @@ static bool wmi_is_pm_resume_cmd(uint32_t cmd_id)
  * @len: wmi buffer length
  * @cmd_id: wmi command id
  *
+ * Note, it is NOT safe to access buf after calling this function!
+ *
  * Return: 0 on success
  */
 QDF_STATUS wmi_unified_cmd_send(wmi_unified_t wmi_handle, wmi_buf_t buf,