doc/scripts: use raw string for regex in gen_state_diagram.py

Python 3.12 emits SyntaxWarning for invalid escape sequences in ordinary
string literals. The re.search() call on line 162 was the only pattern
in the file passed as a non-raw string, causing:

  doc/scripts/gen_state_diagram.py:162: SyntaxWarning: invalid escape
    sequence '\s'
    i = re.search("return\s+transit<\s*(\w*)\s*>()", line)

Add the r"" prefix to match the other re.search / re.finditer / re.sub
call sites in the same file. No behavior change; \s was already being
interpreted as a regex whitespace class because Python leaves unknown
escapes untouched, but this will become a SyntaxError in a future
Python release.

Signed-off-by: Kefu Chai <k.chai@proxmox.com>

diff --git a/doc/scripts/gen_state_diagram.py b/doc/scripts/gen_state_diagram.py
index 50ae23dae8824a5fa64e9004dde5920c5409386a..a8b766cf71262a9cc61f78407fc135fcc6ca2457 100755 (executable)
--- a/doc/scripts/gen_state_diagram.py
+++ b/doc/scripts/gen_state_diagram.py
@@ -159,7 +159,7 @@ class StateMachineRenderer(object):
                 if not self.context:
                     raise Exception("no context at line: " + line)
                 self.edges[i.group(1)].append((self.context[-1][0], i.group(2)))
-        i = re.search("return\s+transit<\s*(\w*)\s*>()", line)
+        i = re.search(r"return\s+transit<\s*(\w*)\s*>()", line)
         if i is not None:
             if not self.context:
                 raise Exception("no context at line: " + line)