staging: rtl8712: Remove NULL comparison

Remove NULL comparison by using '!' operator. Problem found using
checkpatch.pl
CHECK: Comparison to NULL could be written "!padapter->halpriv.hal_bus_init"

Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/staging/rtl8712/hal_init.c b/drivers/staging/rtl8712/hal_init.c
index db0c1de..15c6160 100644
--- a/drivers/staging/rtl8712/hal_init.c
+++ b/drivers/staging/rtl8712/hal_init.c
@@ -382,7 +382,7 @@
 uint rtl871x_hal_init(struct _adapter *padapter)
 {
 	padapter->hw_init_completed = false;
-	if (padapter->halpriv.hal_bus_init == NULL)
+	if (!padapter->halpriv.hal_bus_init)
 		return _FAIL;
 	if (padapter->halpriv.hal_bus_init(padapter) != _SUCCESS)
 		return _FAIL;