memfd_create.test: rewrite from match_grep to match_diff

* tests/memfd_create.c (main): Print expected output.
* tests/memfd_create.test: Use run_strace_match_diff.
* tests/memfd_create.expected: Remove.
* tests/Makefile.am (EXTRA_DIST): Remove it.

tests/Makefile.am

@@ -738,7 +738,6 @@ EXTRA_DIST = init.sh run.sh match.awk \
 	     ipc_msgbuf.expected \
 	     ksysent.sed \
 	     lstatx.c \
-	     memfd_create.expected \
 	     mq.expected \
 	     net.expected \
 	     oldselect.expected \

tests/memfd_create.c

@@ -1,13 +1,21 @@
 #include "tests.h"
-#include <unistd.h>
 #include <sys/syscall.h>
 
 #ifdef __NR_memfd_create
 
+# include <stdio.h>
+# include <unistd.h>
+
 int
 main(void)
 {
-	syscall(__NR_memfd_create, "strace", 7);
+	static const char text[] = "strace";
+	int rc = syscall(__NR_memfd_create, text, 7);
+
+	printf("memfd_create(\"%s\", %s) = %d %s (%m)\n",
+	       text, "MFD_CLOEXEC|MFD_ALLOW_SEALING|0x4", rc, errno2name());
+
+	puts("+++ exited with 0 +++");
 	return 0;
 }
 

tests/memfd_create.expected

@@ -1 +0,0 @@
-memfd_create\("strace", MFD_CLOEXEC\|MFD_ALLOW_SEALING\|0x4\) += -1 .*

tests/memfd_create.test

@@ -1,11 +1,6 @@
 #!/bin/sh
 
-# Check memfd_create syscall decoding.
+# Check decoding of memfd_create syscall.
 
 . "${srcdir=.}/init.sh"
-
-run_prog
-run_strace -e memfd_create $args
-match_grep
-
-exit 0
+run_strace_match_diff