tests: factor out common shell code to functions

Factor out shell code used in several tests to common functions.

* tests/fanotify_mark.expected: New file.
* tests/ioctl.expected: New file.
* tests/net-fd.expected: New file.
* tests/net.expected: New file.
* tests/statfs.expected: New file.
* tests/sun_path.expected: New file.
* tests/uio.expected: New file.
* tests/ipc.sh: New file.
* tests/Makefile.am (EXTRA_DIST): Add them.
* tests/init.sh (dump_log_and_fail_with, run_prog,
run_prog_skip_if_failed, run_strace, run_strace_merge,
match_awk, match_diff, match_grep): New functions.
* tests/*.test: Use them.
diff --git a/tests/statfs.expected b/tests/statfs.expected
new file mode 100755
index 0000000..93e2b51
--- /dev/null
+++ b/tests/statfs.expected
@@ -0,0 +1 @@
+statfs(64)?\("/proc/self/status"(, [1-9][0-9]*)?, \{f_type="PROC_SUPER_MAGIC", f_bsize=[1-9][0-9]*, f_blocks=[0-9]+, f_bfree=[0-9]+, f_bavail=[0-9]+, f_files=[0-9]+, f_ffree=[0-9]+, f_fsid=\{[0-9]+, [0-9]+\}, f_namelen=[1-9][0-9]*(, f_frsize=[0-9]+)?(, f_flags=[0-9]+)?\}\) += 0