[SW-234344] Fix 'RotaryEmbedding' object has no attribute 'sin' (#1658)

## Essential Elements of an Effective PR Description Checklist
- [X] The purpose of the PR, such as "Fix some issue (link existing
issues this PR will resolve)".
- [ ] The test plan, such as providing test command.
- [ ] The test results, such as pasting the results comparison before
and after, or e2e results


## Purpose

Fix issue reported by https://jira.habana-labs.com/browse/SW-234344

## Test Plan

## Test Result

<!--- pyml disable-next-line no-emphasis-as-heading -->

Signed-off-by: Chendi.Xue <[email protected]>

Author: xuechendi

vllm/model_executor/layers/rotary_embedding.py

@@ -268,7 +268,8 @@ def forward_hpu(
         # Prepare cos-sin caches for long-context + LoRA with offsets for every
         # forward, since the offset information wasn't available previously
         if hasattr(self, "scaling_factors") or hasattr(
-                self, "scaling_factor") or self.sin is None:
+                self, "scaling_factor") or not hasattr(
+                    self, "sin") or self.sin is None:
             self.prepare_cos_sin(positions, offsets)
 
         num_tokens = positions.numel()
@@ -812,7 +813,8 @@ def forward_hpu(
         rope_mode: RotaryPosEmbeddingMode
         rope_mode = RotaryPosEmbeddingMode.BLOCKWISE
 
-        if hasattr(self, "scaling_factors") or self.sin is None:
+        if hasattr(self, "scaling_factors") or not hasattr(
+                self, "sin") or self.sin is None:
             self.prepare_cos_sin(positions, offsets)
         if self.recompute_cos_sin:
             self.prepare_cos_sin(positions, offsets, recompute_cos_sin=True)