libluna: Add Result<void>::from_syscall

libluna/include/luna/Result.h

@@ -199,6 +199,13 @@ template <> class Result<void>
         return *this;
     }
 
+    static Result<void> from_syscall(long rc)
+    {
+        if (rc < 0) return Error { -rc };
+
+        return {};
+    }
+
     bool has_error() const
     {
         return m_has_error;

libos/src/FileSystem.cpp

@@ -32,21 +32,15 @@ namespace os::FileSystem
     Result<void> create_directory(StringView path, mode_t mode)
     {
         long rc = syscall(SYS_mkdir, path.chars(), mode);
-        int _ignore = TRY(Result<int>::from_syscall(rc));
 
-        ignore(_ignore);
-
-        return {};
+        return Result<void>::from_syscall(rc);
     }
 
     Result<void> remove(StringView path)
     {
         long rc = syscall(SYS_unlink, path.chars(), 0);
-        int _ignore = TRY(Result<int>::from_syscall(rc));
 
-        ignore(_ignore);
-
-        return {};
+        return Result<void>::from_syscall(rc);
     }
 
     Result<String> working_directory()
@@ -70,10 +64,7 @@ namespace os::FileSystem
     Result<void> change_directory(StringView path)
     {
         long rc = syscall(SYS_chdir, path.chars());
-        int _ignore = TRY(Result<int>::from_syscall(rc));
 
-        ignore(_ignore);
-
-        return {};
+        return Result<void>::from_syscall(rc);
     }
 }