selftests: riscv: vstate_exec_nolibc: Use the regular prctl() function

The my_syscall*() macros are internal implementation details of nolibc.

Now that nolibc has a normal prctl() function, use that.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://patch.msgid.link/20260117-nolibc-mysyscall-riscv-v1-1-0ae1ae3513e9@weissschuh.net
Signed-off-by: Paul Walmsley <pjw@kernel.org>

Author: t-8ch

tools/testing/selftests/riscv/vector/vstate_exec_nolibc.c

@@ -16,10 +16,10 @@ int main(int argc, char **argv)
 	if (argc > 2 && strcmp(argv[2], "x"))
 		xtheadvector = 1;
 
-	ctrl = my_syscall1(__NR_prctl, PR_RISCV_V_GET_CONTROL);
-	if (ctrl < 0) {
+	ctrl = prctl(PR_RISCV_V_GET_CONTROL, 0, 0, 0, 0);
+	if (ctrl == -1) {
 		puts("PR_RISCV_V_GET_CONTROL is not supported\n");
-		return ctrl;
+		exit(-1);
 	}
 
 	if (test_inherit) {
@@ -51,7 +51,7 @@ int main(int argc, char **argv)
 		}
 
 		if (!pid) {
-			rc = my_syscall1(__NR_prctl, PR_RISCV_V_GET_CONTROL);
+			rc = prctl(PR_RISCV_V_GET_CONTROL, 0, 0, 0, 0);
 			if (rc != ctrl) {
 				puts("child's vstate_ctrl not equal to parent's\n");
 				exit(-1);