rename ucore_phi.c phi.c

test/phi.c

@@ -0,0 +1,17 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include "ucore_math.h"
+
+int main(int argc, char *argv[])
+{
+	unsigned int a,N;
+	if (argc < 2) {
+		printf("Usage %s interger1\n",argv[0]);
+		return 1;
+	}
+	a = atoi(argv[1]);
+	N = uc_phi_32(a);
+	printf("phi of %u is %u\n",a,N);
+
+	return 0;
+}