catch ImportError when C code not compiled (#575)

### What this PR does / why we need it?
Found a problem when ImportError raised but not ModuleNotFoundError.


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


### How was this patch tested?
CI passed

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

vllm_ascend/device_allocator/camem.py

@@ -65,7 +65,7 @@ try:
         init_module, python_create_and_map, python_unmap_and_release)
     lib_name = find_loaded_library("vllm_ascend_C")
     camem_available = True
-except ModuleNotFoundError as e:
+except ImportError as e:
     logger.error("Failed to import vllm_ascend_C:%s", e)
     init_module = None
     python_create_and_map = None