Per internal documentation complaint, fix the naming. [(#1933)](GoogleCloudPlatform/python-docs-samples#1933)

The documentation for DLP uses 'dlp' as the instance name.  As this is also the name of the python package, it could be confusing for people new to the API object model so switch to dlp_client.

Author: realjordanna

samples/snippets/quickstart.py

@@ -29,7 +29,7 @@ def quickstart():
     project = 'your-project'
 
     # Instantiate a client.
-    dlp = google.cloud.dlp.DlpServiceClient()
+    dlp_client = google.cloud.dlp.DlpServiceClient()
 
     # The string to inspect
     content = 'Robert Frost'
@@ -59,10 +59,10 @@ def quickstart():
     }
 
     # Convert the project id into a full resource id.
-    parent = dlp.project_path(project)
+    parent = dlp_client.project_path(project)
 
     # Call the API.
-    response = dlp.inspect_content(parent, inspect_config, item)
+    response = dlp_client.inspect_content(parent, inspect_config, item)
 
     # Print out the results.
     if response.result.findings: