Improve cdc_fuse_fs and path (#2)

Improve cdc_fuse_fs and path

Improves the error handling in path so that std:error_codes are not
assumed to be of system category, and also that their messages are
displayed. Also improves debug messages in GameletComponent.

common/errno_mapping.cc

@@ -16,8 +16,6 @@
 
 #include <errno.h>
 
-#include <string>
-
 namespace cdc_ft {
 
 absl::StatusCode ErrnoToCanonicalCode(int error_number) {
@@ -160,10 +158,4 @@ absl::StatusCode ErrnoToCanonicalCode(int error_number) {
   }
 }
 
-absl::Status ErrnoToCanonicalStatus(int error_number,
-                                    absl::string_view message) {
-  return absl::Status(ErrnoToCanonicalCode(error_number),
-                      absl::StrCat(message, ": ", strerror(error_number)));
-}
-
 }  // namespace cdc_ft