Fix cosmetic problems in YAML source

This change corrects problems reported by the `yamllint` linter.

Since key duplication problems were removed in 4d48711, this commit
mainly fixes trailing spaces and extra empty lines at beginning/end of
files.

test/integration/targets/file/tasks/main.yml

@@ -108,7 +108,7 @@
 
 - name: touch a hard link
   file: src={{output_file}} dest={{output_dir}}/hard.txt state=touch
-  register: file6_touch_result  
+  register: file6_touch_result
 
 - name: verify that the hard link was touched
   assert:

test/integration/targets/file/tasks/selinux_tests.yml

@@ -27,4 +27,4 @@
       - "file_se_result.secontext == 'unconfined_u:object_r:admin_home_t:s0'"
 
 - name: remove the file used for testing
-  file: path={{output_dir}}/foo-se.txt state=absent
+  file: path={{output_dir}}/foo-se.txt state=absent