block/raw-win32: Strip "file:" prefix on creation

The bdrv_create() implementation of the block/raw-win32 "file" protocol
driver should strip the "file:" prefix from filenames if present.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

block/raw-win32.c

@@ -481,6 +481,8 @@ static int raw_create(const char *filename, QEMUOptionParameter *options,
     int fd;
     int64_t total_size = 0;
 
+    strstart(filename, "file:", &filename);
+
     /* Read out options */
     while (options && options->name) {
         if (!strcmp(options->name, BLOCK_OPT_SIZE)) {