loader: fixup driver names if needed

This makes it possible to 'use' the imx-drm driver. Remeber that it
is not possible to have sysmbol names in C/C++ with a '-' in it.

Changes since v1:
 - move the fix to loader.c

Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com> (v1)
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>

src/loader/loader.c

@@ -413,5 +413,11 @@ loader_get_extensions_name(const char *driver_name)
    if (asprintf(&name, "%s_%s", __DRI_DRIVER_GET_EXTENSIONS, driver_name) < 0)
       return NULL;
 
+   const size_t len = strlen(name);
+   for (size_t i = 0; i < len; i++) {
+	   if (name[i] == '-')
+		   name[i] = '_';
+   }
+
    return name;
 }