[clang-doc][NFC] Remove unnecessary directory cleanup

The tests all remove the directory at test start, and it only prevents
inspecting the test artifacts to remove them at the end of the test run.

Author: ilovepi

clang-tools-extra/test/clang-doc/single-file-public.cpp

@@ -1,13 +1,11 @@
-// RUN: rm -rf %t
-// RUN: mkdir %t
+// RUN: rm -rf %t && mkdir -p %t
 // RUN: echo "" > %t/compile_flags.txt
 // RUN: cp "%s" "%t/test.cpp"
 // RUN: clang-doc --doxygen --public --executor=standalone -p %t %t/test.cpp -output=%t/docs
 //   This produces two files, index.yaml and one for the record named by its USR
 //   (which we don't know in advance). This checks the record file by searching
 //   for a name with a 40-char USR name.
 // RUN: find %t/docs -regex ".*/[0-9A-F]*.yaml" -exec cat {} ";" | FileCheck %s --check-prefix=CHECK
-// RUN: rm -rf %t
 
 class Record {
 private:

clang-tools-extra/test/clang-doc/single-file.cpp

@@ -1,10 +1,8 @@
-// RUN: rm -rf %t
-// RUN: mkdir %t
+// RUN: rm -rf %t && mkdir -p %t
 // RUN: echo "" > %t/compile_flags.txt
 // RUN: cp "%s" "%t/test.cpp"
 // RUN: clang-doc --doxygen --executor=standalone -p %t %t/test.cpp -output=%t/docs
 // RUN: cat %t/docs/index.yaml | FileCheck %s --check-prefix=CHECK
-// RUN: rm -rf %t
 
 void function(int x);
 

clang-tools-extra/test/clang-doc/test-path-abs.cpp

@@ -1,6 +1,6 @@
-// RUN: rm -rf %t && mkdir %t
+// RUN: rm -rf %t && mkdir -p %t
 // RUN: clang-doc --format=html --executor=standalone %s --output=%t
 // RUN: FileCheck %s -input-file=%t/index_json.js  -check-prefix=JSON-INDEX
-// RUN: rm -rf %t
 
-// JSON-INDEX: var RootPath = "{{.*}}test-path-abs.cpp.tmp";
+// JSON-INDEX: var RootPath = "{{.*}}test-path-abs.cpp.tmp";
+