qcacmn: Remove redundant null check for wmi_handle

In WMI detach caller routine already has null check for
wmi_handle so remove redundant null check.

Change-Id: I764a91a6050ffc93613b82008f5df2529a056e70
CRs-Fixed: 1027177
diff --git a/wmi_unified.c b/wmi_unified.c
index c3473e6..a32259f 100644
--- a/wmi_unified.c
+++ b/wmi_unified.c
@@ -2203,10 +2203,8 @@
 	qdf_spin_unlock_bh(&wmi_handle->eventq_lock);
 	qdf_spinlock_destroy(&wmi_handle->eventq_lock);
 	qdf_spinlock_destroy(&wmi_handle->ctx_lock);
-	if (wmi_handle != NULL) {
-		OS_FREE(wmi_handle);
-		wmi_handle = NULL;
-	}
+	OS_FREE(wmi_handle);
+	wmi_handle = NULL;
 }
 
 /**