ion: convert map_kernel to return ERR_PTR

ion is going to stop accepting NULL as an error value, use ERR_PTR.
Signed-off-by: Colin Cross <ccross@android.com>
[jstultz: modified patch to apply to staging directory]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/android/ion/ion_carveout_heap.c

@@ -112,13 +112,18 @@ void ion_carveout_heap_unmap_dma(struct ion_heap *heap,
 void *ion_carveout_heap_map_kernel(struct ion_heap *heap,
 				   struct ion_buffer *buffer)
 {
+	void *ret;
 	int mtype = MT_MEMORY_NONCACHED;
 
 	if (buffer->flags & ION_FLAG_CACHED)
 		mtype = MT_MEMORY;
 
-	return __arm_ioremap(buffer->priv_phys, buffer->size,
+	ret = __arm_ioremap(buffer->priv_phys, buffer->size,
 			      mtype);
+	if (ret == NULL)
+		return ERR_PTR(-ENOMEM);
+
+	return ret;
 }
 
 void ion_carveout_heap_unmap_kernel(struct ion_heap *heap,

drivers/staging/android/ion/ion_heap.c

@@ -56,6 +56,9 @@ void *ion_heap_map_kernel(struct ion_heap *heap,
 	vaddr = vmap(pages, npages, VM_MAP, pgprot);
 	vfree(pages);
 
+	if (vaddr == NULL)
+		return ERR_PTR(-ENOMEM);
+
 	return vaddr;
 }