Fix ninjalog_uploader.py to exclude /path/to/depot_tools/ninja.py

Bug: b/270907050
Change-Id: I2bb5ffbb9ae8590078c92e2c7e0095f28f0c21be
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/4297356
Auto-Submit: Junji Watanabe <jwata@google.com>
Reviewed-by: Takuto Ikuta <tikuta@chromium.org>
Commit-Queue: Dirk Pranke <dpranke@google.com>
Reviewed-by: Dirk Pranke <dpranke@google.com>

ninjalog_uploader.py

@@ -75,8 +75,8 @@ def ParseGNArgs(gn_args):
 def GetBuildTargetFromCommandLine(cmdline):
   """Get build targets from commandline."""
 
-  # Skip argv0.
-  idx = 1
+  # Skip argv0, argv1: ['/path/to/python3', '/path/to/depot_tools/ninja.py']
+  idx = 2
 
   # Skipping all args that involve these flags, and taking all remaining args
   # as targets.