Fix libretrodb_open - change mode to RFILE_MODE_READ - use

buffered I/O by default

libretro-common/file/retro_file.c

@@ -38,7 +38,7 @@
 #include <fcntl.h>
 #endif
 
-#if 0
+#if 1
 #define HAVE_BUFFERED_IO 1
 #endif
 

libretro-db/libretrodb.c

@@ -191,7 +191,7 @@ int libretrodb_open(const char *path, libretrodb_t *db)
    libretrodb_header_t header;
    libretrodb_metadata_t md;
    int rv;
-   RFILE *fd = retro_fopen(path, RFILE_MODE_READ_WRITE, -1);
+   RFILE *fd = retro_fopen(path, RFILE_MODE_READ, -1);
 
    if (!fd)
       return -errno;