Undefined name: 'target' --> 'self.target'

[cclauss]

🎄 flake8 testing of https://github.com/janeasystems/nodejs-mobile-gyp on Python 2.7.15

$ flake8 . --count --select=E901,E999,F821,F822,F823 --show-source --statistics

./gyp/gyptest.py:74:17: F821 undefined name 'shlex'
      cmdargs = shlex.split(command)
                ^
./gyp/pylib/gyp/mac_tool.py:128:12: F821 undefined name 'e'
    except e:
           ^
./gyp/pylib/gyp/generator/xcode.py:705:9: F821 undefined name 'self'
    if (self.flavor == 'ios'):
        ^
./gyp/pylib/gyp/generator/make.py:1631:50: F821 undefined name 'target'
      print "WARNING: no output for", self.type, target
                                                 ^
4     F821 undefined name 'shlex'
4

Checklist

• [ ] npm install && npm test passes
• [ ] tests are included
• [ ] documentation is changed or added
• [ ] commit message follows commit guidelines

Description of change