bios_emulator: remove assignment without effect

Assigning a parameter which is not used afterwards has not effect.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/bios_emulator/atibios.c b/drivers/bios_emulator/atibios.c
index 4a16fc7..4f362d1 100644
--- a/drivers/bios_emulator/atibios.c
+++ b/drivers/bios_emulator/atibios.c
@@ -606,7 +606,6 @@
 		    (ulong)(vga_info->BIOSImage) != 0xc0000)
 			free(vga_info->BIOSImage);
 		free(vga_info);
-		vga_info = NULL;
 	}
 
 	return 0;