Fix nio read/write pseudo files

[achyuki]

Since this commit, on Linux kernel versions 5.10 and later, splice syscalls for some pseudo files that do not implement splice_read (such as /configfs and /proc/config.gz) will no longer be available and will throw an EINVAL error. Previously, they worked correctly.

Log:

1765217146.998 10322 13163 14367 E EXAMPLE : Caused by: android.system.ErrnoException: splice failed: EINVAL (Invalid argument)
1765217146.998 10322 13163 14367 E EXAMPLE : at libcore.io.Linux.splice(Native Method)
1765217146.998 10322 13163 14367 E EXAMPLE : at libcore.io.ForwardingOs.splice(ForwardingOs.java:831)
1765217146.998 10322 13163 14367 E EXAMPLE : at libcore.io.BlockGuardOs.splice(BlockGuardOs.java:513)
1765217146.998 10322 13163 14367 E EXAMPLE : at android.system.Os.splice(Os.java:899)
1765217146.998 10322 13163 14367 E EXAMPLE : at java.lang.reflect.Method.invoke(Native Method)
1765217146.998 10322 13163 14367 E EXAMPLE : at com.topjohnwu.superuser.internal.OpenFile.pread(OpenFile.java:122)
1765217146.998 10322 13163 14367 E EXAMPLE : at com.topjohnwu.superuser.internal.FileUtils.splice(FileUtils.java:164)
1765217146.998 10322 13163 14367 E EXAMPLE : at com.topjohnwu.superuser.internal.FileSystemService.pread(FileSystemService.java:270)
1765217146.998 10322 13163 14367 E EXAMPLE : at com.topjohnwu.superuser.internal.IFileSystemService$Stub.onTransact(IFileSystemService.java:492)
1765217146.998 10322 13163 14367 E EXAMPLE : at android.os.Binder.execTransactInternal(Binder.java:1285)
1765217146.998 10322 13163 14367 E EXAMPLE : at android.os.Binder.execTransact(Binder.java:1249)