tests: add xetpriority.test

* resource.c (SYS_FUNC(getpriority), SYS_FUNC(setpriority)): Print
the second syscall argument using %d format.
* tests/xetpriority.c: New file.
* tests/xetpriority.test: New test.
* tests/.gitignore: Add xetpriority.
* tests/Makefile.am (check_PROGRAMS): Likewise.
(TESTS): Add xetpriority.test.
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 6590f95..3005382 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -197,6 +197,7 @@
 	xet_robust_list \
 	xetitimer \
 	xetpgid \
+	xetpriority \
 	xettimeofday \
 	# end of check_PROGRAMS
 
@@ -365,6 +366,7 @@
 	xet_robust_list.test \
 	xetitimer.test \
 	xetpgid.test \
+	xetpriority.test \
 	xettimeofday.test \
 	\
 	count.test \