setrlimit01.c: use a more reliable segfault

When compiled for Android, strcpying to the null pointer was being
optimized away as unreachable, so the segfault wasn't being thrown.  Use
raise to throw the segfault instead of ub, since the test just needs the
signal.

Reviewed-by: Andrea Cervesato <andrea.cervesato@suse.com>
Signed-off-by: Edward Liaw <edliaw@google.com>

Author: Edward Liaw via ltp

testcases/kernel/syscalls/setrlimit/setrlimit01.c

@@ -33,6 +33,7 @@
 #include <sys/wait.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <signal.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include "test.h"
@@ -256,8 +257,7 @@ static void test4(void)
 		tst_brkm(TBROK, cleanup, "fork() failed");
 
 	if (pid == 0) {		/* child */
-		char *testbuf = NULL;
-		strcpy(testbuf, "abcd");
+		raise(SIGSEGV);
 		exit(0);
 	}
 	wait(&status);