[lldb/Utility] Update path in FileSpec documentation (NFC)

Update FileSpec doxygen path to reflect its actual location in the
source-tree.

Signed-off-by: Med Ismail Bennani <[email protected]>

Author: medismailben

lldb/include/lldb/Utility/FileSpec.h

@@ -38,7 +38,7 @@ template <typename T> class SmallVectorImpl;
 
 namespace lldb_private {
 
-/// \class FileSpec FileSpec.h "lldb/Host/FileSpec.h"
+/// \class FileSpec FileSpec.h "lldb/Utility/FileSpec.h"
 /// A file utility class.
 ///
 /// A file specification class that divides paths up into a directory