[clang-tidy] Refactor: Move misc clang-tidy checks to namespace clang::tidy::misc

clang-tidy checks are organized into modules. This refactoring moves the misc
module checks into the namespace clang::tidy::misc

http://reviews.llvm.org/D7996

Patch by Richard Thomson!

llvm-svn: 230950
diff --git a/clang-tools-extra/clang-tidy/misc/InefficientAlgorithmCheck.h b/clang-tools-extra/clang-tidy/misc/InefficientAlgorithmCheck.h
index f55297f..0148813 100644
--- a/clang-tools-extra/clang-tidy/misc/InefficientAlgorithmCheck.h
+++ b/clang-tools-extra/clang-tidy/misc/InefficientAlgorithmCheck.h
@@ -14,6 +14,7 @@
 
 namespace clang {
 namespace tidy {
+namespace misc {
 
 /// \brief Warns on inefficient use of STL algorithms on associative containers.
 ///
@@ -28,6 +29,7 @@
   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
 };
 
+} // namespace misc
 } // namespace tidy
 } // namespace clang