read/macho: fix data for segments in dyld caches

Note that this is only for operations on the segment itself.
Sections within the segment were already using the correct data.

src/read/macho/segment.rs

@@ -69,7 +69,7 @@ where
     fn bytes(&self) -> Result<&'data [u8]> {
         self.internal
             .segment
-            .data(self.file.endian, self.file.data)
+            .data(self.file.endian, self.internal.data)
             .read_error("Invalid Mach-O segment size or offset")
     }
 }