pvmfw: fdt: Use RangeExt as _

Keep the trait anonymous.

Test: TH
Change-Id: I42ec969d3e2b803d114903c7133c20a60bef2d82
diff --git a/pvmfw/src/fdt.rs b/pvmfw/src/fdt.rs
index 70916ac..bda35a7 100644
--- a/pvmfw/src/fdt.rs
+++ b/pvmfw/src/fdt.rs
@@ -17,7 +17,7 @@
 use crate::bootargs::BootArgsIterator;
 use crate::cstr;
 use crate::helpers::flatten;
-use crate::helpers::RangeExt;
+use crate::helpers::RangeExt as _;
 use crate::helpers::GUEST_PAGE_SIZE;
 use crate::helpers::SIZE_4KB;
 use crate::memory::BASE_ADDR;