fix SDWebImage#610

Author: foxling

SDWebImage/SDWebImageDownloaderOperation.m

@@ -228,8 +228,7 @@ - (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
         const NSInteger totalSize = self.imageData.length;
 
         // Update the data source, we must pass ALL the data, not just the new bytes
-        CGImageSourceRef imageSource = CGImageSourceCreateIncremental(NULL);
-        CGImageSourceUpdateData(imageSource, (__bridge CFDataRef)self.imageData, totalSize == self.expectedSize);
+        CGImageSourceRef imageSource = CGImageSourceCreateWithData((__bridge CFDataRef)self.imageData, NULL);
 
         if (width + height == 0) {
             CFDictionaryRef properties = CGImageSourceCopyPropertiesAtIndex(imageSource, 0, NULL);