bpo-41687: Fix error handling in Solaris sendfile implementation (GH-22128)

I just realized that my recent PR with sendfile on Solaris ([PR 22040](https://github.com/python/cpython/pull/22040)) has broken error handling.

Sorry for that, this simple followup fixes that.

Automerge-Triggered-By: @1st1
(cherry picked from commit fa8c9e70104b0aef966a518eb3a80a4881906ae0)

Co-authored-by: Jakub Kulík <Kulikjak@gmail.com>

diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 39f5f577a8286f44d52885a9c94599630b0f4903..01e8bcbd2981a476d1f6b5057d1fb73a53e5490c 100644 (file)
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -9456,14 +9456,13 @@ done:
 #if defined(__sun) && defined(__SVR4)
     // On Solaris, sendfile raises EINVAL rather than returning 0
     // when the offset is equal or bigger than the in_fd size.
-    int res;
     struct stat st;
 
     do {
         Py_BEGIN_ALLOW_THREADS
-        res = fstat(in_fd, &st);
+        ret = fstat(in_fd, &st);
         Py_END_ALLOW_THREADS
-    } while (res != 0 && errno == EINTR && !(async_err = PyErr_CheckSignals()));
+    } while (ret != 0 && errno == EINTR && !(async_err = PyErr_CheckSignals()));
     if (ret < 0)
         return (!async_err) ? posix_error() : NULL;