flake8: make entire repository pass spack flake8 -a

- Fix trailing whitespace missed by the bug described in #12755.

- Fix other style issues that have crept in over time (this can happen
  when flake8 adds new checks with new versions)

var/spack/repos/builtin/packages/ccs-qcd/package.py

@@ -33,14 +33,12 @@ class CcsQcd(MakefilePackage):
     version('master', branch='master')
     version('1.2.1', commit='d7c6b6923f35a824e997ba8db5bd12dc20dda45c')
 
-    variant(
-        'class', values=int, default=1,
-        description='This miniapp has five problem classes, for which the' +
-            ' first three are relatively small problems just for testing' +
-            ' this miniapp itself. The remaining two are the target problem' +
+    variant('class', values=int, default=1,
+            description='This miniapp has five problem classes, for which the'
+            ' first three are relatively small problems just for testing'
+            ' this miniapp itself. The remaining two are the target problem'
             ' sizes for the HPCI FS evaluation.',
-        multi=False, validator=class_validator
-    )
+            multi=False, validator=class_validator)
 
     depends_on('mpi')