mctp-bench: remove prctl includes

Khem reports that including both linux/prctl.h and sys/prctl.h appears
to break builds with musl:

    In file included from ../sources/mctp-2.3/src/mctp-bench.c:16:
    ../recipe-sysroot/usr/include/sys/prctl.h:88:8: error: redefinition of 'prctl_mm_map'
       88 | struct prctl_mm_map {
          |        ^
    ../recipe-sysroot/usr/include/linux/prctl.h:134:8: note: previous definition is here
      134 | struct prctl_mm_map {
          |        ^

We're not using prctl() at present, so both can be removed.

Reported-by: Khem Raj <[email protected]>
Signed-off-by: Jeremy Kerr <[email protected]>

Author: jk-ozlabs

CHANGELOG.md

@@ -6,6 +6,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ## [Unreleased]
 
+### Fixed
+
+1. Fixed `mctp-bench` compile on musl libc
+
 ## [2.3] - 2025-10-22
 
 ### Fixed

src/mctp-bench.c

@@ -12,8 +12,6 @@
 #include <sys/socket.h>
 #include <time.h>
 #include <unistd.h>
-#include <linux/prctl.h>
-#include <sys/prctl.h>
 #include <assert.h>
 #include <sys/random.h>