telemetrygen: Fix incorrect error in log line (open-telemetry#31362)

**Description:**
Incorrect error is used in logger.Error within telemetrygen traces.

.chloggen/telemetrygen-fix-log-incorrect-error.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: cmd/telemetrygen
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Fix incorrect error logged in traces batch span processor shutdown
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [31362]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: []

cmd/telemetrygen/internal/traces/traces.go

@@ -73,7 +73,7 @@ func Start(cfg *Config) error {
 		defer func() {
 			logger.Info("stop the batch span processor")
 			if tempError := ssp.Shutdown(context.Background()); tempError != nil {
-				logger.Error("failed to stop the batch span processor", zap.Error(err))
+				logger.Error("failed to stop the batch span processor", zap.Error(tempError))
 			}
 		}()
 	}