[Misc] set single whitespace between log sentences (#13771)

Signed-off-by: cjackal <44624812+cjackal@users.noreply.github.com>

vllm/v1/worker/gpu_worker.py

@@ -277,5 +277,5 @@ def _check_if_gpu_supports_dtype(torch_dtype: torch.dtype):
             raise ValueError(
                 "Bfloat16 is only supported on GPUs with compute capability "
                 f"of at least 8.0. Your {gpu_name} GPU {compute_str}. "
-                "You can use float16 instead by explicitly setting the"
+                "You can use float16 instead by explicitly setting the "
                 "`dtype` flag in CLI, for example: --dtype=half.")