rust: Only apply hwasan flags once to fuzz targets

On HWASAN global sanitized builds, fuzz targets had hwasanFlags applied
twice. Rust only allows llvm-args flags to be passed in once however, so
this broke compilation.

Bug: 204915322
Test: SANITIZE_TARGET='hwaddress fuzzer' m <fuzzer>
Change-Id: I4f6c35e04bc4c891d9c66e8a53c3dcb88e8670cf
diff --git a/rust/sanitize.go b/rust/sanitize.go
index fdb342d..5318be3 100644
--- a/rust/sanitize.go
+++ b/rust/sanitize.go
@@ -237,12 +237,10 @@
 		} else {
 			flags.RustFlags = append(flags.RustFlags, asanFlags...)
 		}
-	}
-	if Bool(sanitize.Properties.Sanitize.Address) {
-		flags.RustFlags = append(flags.RustFlags, asanFlags...)
-	}
-	if Bool(sanitize.Properties.Sanitize.Hwaddress) {
+	} else if Bool(sanitize.Properties.Sanitize.Hwaddress) {
 		flags.RustFlags = append(flags.RustFlags, hwasanFlags...)
+	} else if Bool(sanitize.Properties.Sanitize.Address) {
+		flags.RustFlags = append(flags.RustFlags, asanFlags...)
 	}
 	return flags, deps
 }