kernel/server_port: Change error case return value in Accept() to ERR_NOT_FOUND

This is what the kernel does in this instance.

src/core/hle/kernel/errors.h

@@ -69,7 +69,5 @@ constexpr ResultCode ERR_NOT_AUTHORIZED(-1);
 constexpr ResultCode ERR_INVALID_HANDLE_OS(-1);
 constexpr ResultCode ERR_NOT_FOUND(ErrorModule::Kernel, ErrCodes::NoSuchEntry);
 constexpr ResultCode RESULT_TIMEOUT(ErrorModule::Kernel, ErrCodes::Timeout);
-/// Returned when Accept() is called on a port with no sessions to be accepted.
-constexpr ResultCode ERR_NO_PENDING_SESSIONS(-1);
 
 } // namespace Kernel

src/core/hle/kernel/server_port.cpp

@@ -18,7 +18,7 @@ ServerPort::~ServerPort() = default;
 
 ResultVal<SharedPtr<ServerSession>> ServerPort::Accept() {
     if (pending_sessions.empty()) {
-        return ERR_NO_PENDING_SESSIONS;
+        return ERR_NOT_FOUND;
     }
 
     auto session = std::move(pending_sessions.back());