Use /twres instead of /res for theme resources

AOSP and other ROM trees now do a rm -rf of the res folder during
the ramdisk creation process that removes the TWRP resources.
Using /twres instead of /res works around this issue making TWRP
more compatible with AOSP and other build trees.

Change-Id: I0d4c7e06ca381ac5aa0069b6f2b8c47f7dec49e7
diff --git a/minuitwrp/graphics.c b/minuitwrp/graphics.c
index d08e743..512a957 100644
--- a/minuitwrp/graphics.c
+++ b/minuitwrp/graphics.c
@@ -626,7 +626,7 @@
     {
         char tmp[128];
 
-        sprintf(tmp, "/res/fonts/%s.dat", fontName);
+        sprintf(tmp, TWRES "fonts/%s.dat", fontName);
         fd = open(tmp, O_RDONLY);
         if (fd == -1)
             return NULL;