samples/bpf: adjust rlimit RLIMIT_MEMLOCK for xdp1

Default rlimit RLIMIT_MEMLOCK is 64KB, causes bpf map failure.
e.g.
[root@lab bpf]#./xdp1 -N $(</sys/class/net/eth2/ifindex)
failed to create a map: 1 Operation not permitted

Fix it.
Signed-off-by: Tushar Dave <tushar.n.dave@oracle.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

samples/bpf/xdp1_user.c

@@ -14,6 +14,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <libgen.h>
+#include <sys/resource.h>
 
 #include "bpf_load.h"
 #include "bpf_util.h"
@@ -69,6 +70,7 @@ static void usage(const char *prog)
 
 int main(int argc, char **argv)
 {
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
 	const char *optstr = "SN";
 	char filename[256];
 	int opt;
@@ -91,6 +93,12 @@ int main(int argc, char **argv)
 		usage(basename(argv[0]));
 		return 1;
 	}
+
+	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
+		perror("setrlimit(RLIMIT_MEMLOCK)");
+		return 1;
+	}
+
 	ifindex = strtoul(argv[optind], NULL, 0);
 
 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);