test: remove duplicated test

`test_atomic_accesses` in `guest_memory.rs` is exactly the same as
`test_atomic_accesses` in `mmap.rs`, so delete the former.

Signed-off-by: Patrick Roy <roypat@amazon.co.uk>

Author: roypat

src/guest_memory.rs

@@ -829,16 +829,6 @@ mod tests {
             .is_ok());
     }
 
-    #[cfg(feature = "backend-mmap")]
-    #[test]
-    fn test_atomic_accesses() {
-        let addr = GuestAddress(0x1000);
-        let mem = GuestMemoryMmap::from_ranges(&[(addr, 0x1000)]).unwrap();
-        let bad_addr = addr.unchecked_add(0x1000);
-
-        crate::bytes::tests::check_atomic_accesses(mem, addr, bad_addr);
-    }
-
     #[cfg(feature = "backend-mmap")]
     #[cfg(target_os = "linux")]
     #[test]