staging: rtl8188eu: fix comparsions to NULL - coding style

Use !x instead of x == NULL.
Signed-off-by: Michael Straube <straube.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8188eu/core/rtw_xmit.c

@@ -70,7 +70,7 @@ s32	_rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter)
 
 	pxmitpriv->pallocated_frame_buf = vzalloc(NR_XMITFRAME * sizeof(struct xmit_frame) + 4);
 
-	if (pxmitpriv->pallocated_frame_buf  == NULL) {
+	if (!pxmitpriv->pallocated_frame_buf) {
 		pxmitpriv->pxmit_frame_buf = NULL;
 		RT_TRACE(_module_rtl871x_xmit_c_, _drv_err_, ("alloc xmit_frame fail!\n"));
 		res = _FAIL;
@@ -108,7 +108,7 @@ s32	_rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter)
 
 	pxmitpriv->pallocated_xmitbuf = vzalloc(NR_XMITBUFF * sizeof(struct xmit_buf) + 4);
 
-	if (pxmitpriv->pallocated_xmitbuf  == NULL) {
+	if (!pxmitpriv->pallocated_xmitbuf) {
 		RT_TRACE(_module_rtl871x_xmit_c_, _drv_err_, ("alloc xmit_buf fail!\n"));
 		res = _FAIL;
 		goto exit;
@@ -149,7 +149,7 @@ s32	_rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter)
 
 	pxmitpriv->pallocated_xmit_extbuf = vzalloc(num_xmit_extbuf * sizeof(struct xmit_buf) + 4);
 
-	if (pxmitpriv->pallocated_xmit_extbuf  == NULL) {
+	if (!pxmitpriv->pallocated_xmit_extbuf) {
 		RT_TRACE(_module_rtl871x_xmit_c_, _drv_err_, ("alloc xmit_extbuf fail!\n"));
 		res = _FAIL;
 		goto exit;
@@ -210,7 +210,7 @@ void _rtw_free_xmit_priv(struct xmit_priv *pxmitpriv)
 	struct xmit_buf *pxmitbuf = (struct xmit_buf *)pxmitpriv->pxmitbuf;
 	u32 num_xmit_extbuf = NR_XMIT_EXTBUFF;
 
-	if (pxmitpriv->pxmit_frame_buf == NULL)
+	if (!pxmitpriv->pxmit_frame_buf)
 		return;
 
 	for (i = 0; i < NR_XMITFRAME; i++) {
@@ -941,7 +941,7 @@ s32 rtw_xmitframe_coalesce(struct adapter *padapter, struct sk_buff *pkt, struct
 	if (!psta)
 		return _FAIL;
 
-	if (pxmitframe->buf_addr == NULL) {
+	if (!pxmitframe->buf_addr) {
 		DBG_88E("==> %s buf_addr == NULL\n", __func__);
 		return _FAIL;
 	}