Remove \brief commands from doxygen comments.

This is similar to the LLVM change https://reviews.llvm.org/D46290.

We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

for i in $(git grep -l '\@brief'); do perl -pi -e 's/\@brief //g' $i & done
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46320

llvm-svn: 331834
diff --git a/clang/lib/StaticAnalyzer/Frontend/ModelInjector.h b/clang/lib/StaticAnalyzer/Frontend/ModelInjector.h
index 98a5f69..b1b6de9 100644
--- a/clang/lib/StaticAnalyzer/Frontend/ModelInjector.h
+++ b/clang/lib/StaticAnalyzer/Frontend/ModelInjector.h
@@ -8,7 +8,7 @@
 //===----------------------------------------------------------------------===//
 ///
 /// \file
-/// \brief This file defines the clang::ento::ModelInjector class which implements the
+/// This file defines the clang::ento::ModelInjector class which implements the
 /// clang::CodeInjector interface. This class is responsible for injecting
 /// function definitions that were synthesized from model files.
 ///
@@ -43,7 +43,7 @@
   Stmt *getBody(const ObjCMethodDecl *D) override;
 
 private:
-  /// \brief Synthesize a body for a declaration
+  /// Synthesize a body for a declaration
   ///
   /// This method first looks up the appropriate model file based on the
   /// model-path configuration option and the name of the declaration that is