docs: Update broken link in snapshotting documentation

Update the broken link of page faults handler process example.

Signed-off-by: Char1ee <[email protected]>

Author: char-1ee

docs/snapshotting/handling-page-faults-on-snapshot-resume.md

@@ -127,7 +127,7 @@ unexpected cases when Firecracker crashes before being able to connect/send data
 
 ### Example
 
-An example of a handler process can be found [here](../../tests/host_tools/uffd/src/bin/valid_handler.rs).
+An example of a handler process can be found [here](../../src/firecracker/examples/uffd/valid_handler.rs).
 The process is designed to tackle faults on a certain address by loading into
 memory the entire region that the address belongs to, but users can choose any
 other behavior that suits their use case best.