fix for long line warnings

This is preparation CL for https://crrev.com/c/5035265.

Change-Id: I9ab8ffed471d3813a0e94bbdb47bf95e3bb46337
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/5036119
Commit-Queue: Philipp Wollermann <philwo@chromium.org>
Reviewed-by: Philipp Wollermann <philwo@chromium.org>
Auto-Submit: Takuto Ikuta <tikuta@chromium.org>

post_build_ninja_summary.py

@@ -121,8 +121,8 @@ def ReadTargets(log, show_all):
     # targets.
     if not header:
         return []
-    assert header == '# ninja log v5\n', \
+    assert header == '# ninja log v5\n', ('unrecognized ninja log version %r' %
-           'unrecognized ninja log version %r' % header
+                                          header)
     targets_dict = {}
     last_end_seen = 0.0
     for line in log:
@@ -166,8 +166,8 @@ def GetExtension(target, extra_patterns):
     """Return the file extension that best represents a target.
 
     For targets that generate multiple outputs it is important to return a
-  consistent 'canonical' extension. Ultimately the goal is to group build steps
+    consistent 'canonical' extension. Ultimately the goal is to group build
-  by type."""
+    steps by type."""
     for output in target.targets:
         if extra_patterns:
             for fn_pattern in extra_patterns.split(';'):