Tests: Add a test that RC16 must be supported when SBC3 is claimed

Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>

test-tool/iscsi-test-cu.h

@@ -165,6 +165,7 @@ void test_readcapacity10_simple(void);
 void test_readcapacity16_alloclen(void);
 void test_readcapacity16_protection(void);
 void test_readcapacity16_simple(void);
+void test_readcapacity16_support(void);
 
 void test_readonly_sbc(void);