[Bugfix] [0.7.3] fix log output bug when calling npu_mrope (#911)

### What this PR does / why we need it?

Fix #825 

### Does this PR introduce _any_ user-facing change?
No

### How was this patch tested?
With CI

Signed-off-by: Shuqiao Li <celestialli@outlook.com>

Author: celestialli

vllm_ascend/ops/rotary_embedding.py

@@ -15,6 +15,7 @@
 # limitations under the License.
 #
 
+import os
 from typing import Optional, Tuple
 
 import torch
@@ -87,6 +88,25 @@ def rope_deepseek_forward_oot(
     return query, key
 
 
+class support_stdout_stderr(object):
+
+    def __init__(self):
+        self.null_fds = [os.open(os.devnull, os.O_RDWR) for x in range(2)]
+        self.save_fds = (os.dup(1), os.dup(2))
+
+    def __enter__(self):
+        os.dup2(self.null_fds[0], 1)
+        os.dup2(self.null_fds[1], 2)
+
+    def __exit__(self, *_):
+        os.dup2(self.save_fds[0], 1)
+        os.dup2(self.save_fds[1], 2)
+        os.close(self.null_fds[0])
+        os.close(self.null_fds[1])
+        os.close(self.save_fds[0])
+        os.close(self.save_fds[1])
+
+
 def mrope_forward(
     self,
     positions: torch.Tensor,
@@ -95,13 +115,14 @@ def mrope_forward(
 ) -> Tuple[torch.Tensor, torch.Tensor]:
     import torch_npu
     mrope_section = [0, 0, 0] if positions.ndim == 1 else self.mrope_section
-    query, key = torch_npu.npu_mrope(positions,
-                                     query.contiguous(),
-                                     key.contiguous(),
-                                     self.cos_sin_cache.contiguous(),
-                                     self.head_size,
-                                     mrope_section=mrope_section,
-                                     rotary_mode='half')
+    with support_stdout_stderr():
+        query, key = torch_npu.npu_mrope(positions,
+                                         query.contiguous(),
+                                         key.contiguous(),
+                                         self.cos_sin_cache.contiguous(),
+                                         self.head_size,
+                                         mrope_section=mrope_section,
+                                         rotary_mode='half')
     return query, key