IR: fix documentation markup

Use `\brief` instead of `\Brief`.  NFC.

llvm-svn: 334627

Author: compnerd

llvm/include/llvm/IR/Attributes.h

@@ -465,12 +465,12 @@ class AttributeList {
     return removeAttributes(C, ArgNo + FirstArgIndex);
   }
 
-  /// \Brief Add the dereferenceable attribute to the attribute set at the given
+  /// \brief Add the dereferenceable attribute to the attribute set at the given
   /// index. Returns a new list because attribute lists are immutable.
   AttributeList addDereferenceableAttr(LLVMContext &C, unsigned Index,
                                        uint64_t Bytes) const;
 
-  /// \Brief Add the dereferenceable attribute to the attribute set at the given
+  /// \brief Add the dereferenceable attribute to the attribute set at the given
   /// arg index. Returns a new list because attribute lists are immutable.
   AttributeList addDereferenceableParamAttr(LLVMContext &C, unsigned ArgNo,
                                             uint64_t Bytes) const {