staging: sm750fb: Replace NULL comparison.

Replaced NULL comparison with pCurrentDviCtrl->pfnInit. This patch fixes
the following checkpatch issue:

CHECK: Comparison to NULL could be written "pCurrentDviCtrl->pfnInit"
Signed-off-by: Varsha Rao <rvarsha016@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/sm750fb/ddk750_dvi.c

@@ -45,7 +45,7 @@ int dviInit(
 	dvi_ctrl_device_t *pCurrentDviCtrl;
 
 	pCurrentDviCtrl = g_dcftSupportedDviController;
-	if (pCurrentDviCtrl->pfnInit != NULL) {
+	if (pCurrentDviCtrl->pfnInit) {
 		return pCurrentDviCtrl->pfnInit(edgeSelect, busSelect, dualEdgeClkSelect, hsyncEnable,
 						vsyncEnable, deskewEnable, deskewSetting, continuousSyncEnable,
 						pllFilterEnable, pllFilterValue);