staging: omap-thermal: fix return value

Return the proper error value in _omap_bandgap_read_threshold.
Acked-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NEduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/omap-thermal/omap-bandgap.c

@@ -566,7 +566,7 @@ int _omap_bandgap_read_threshold(struct omap_bandgap *bg_ptr, int id,
 	*val = temp;
 
 exit:
-	return 0;
+	return ret;
 }
 
 /***   Exposed APIs   ***/