Fix a couple of "make check" issues

There was some logic copied from bitstring.c and an unused variable
problem reported by the compiler.

testsuite/slurm_unit/common/bitstring-test.c

@@ -5,6 +5,12 @@
 #include <sys/time.h>
 #include <testsuite/dejagnu.h>
 
+/* Copied from src/common/bitstring.c */
+#define	_bitstr_words(nbits)	\
+	((((nbits) + BITSTR_MAXPOS) >> BITSTR_SHIFT) + BITSTR_OVERHEAD)
+#define	bit_decl(name, nbits) \
+	(name)[_bitstr_words(nbits)] = { BITSTR_MAGIC_STACK, (nbits) }
+
 /* Test for failure: 
 */
 #define TEST(_tst, _msg) do {		\

testsuite/slurm_unit/common/pack-test.c

@@ -69,7 +69,7 @@ int main (int argc, char *argv[])
 
   	unpack64(&test64, buffer);
 	test_double2 = (long double)test64;
-	TEST(test64 != (uint64_t)test_double, "un/pack double as a uint64");
+	TEST((uint64_t)test_double2 != (uint64_t)test_double, "un/pack double as a uint64");
 	/* info("Original\t %Lf", test_double); */
 	/* info("uint64\t %ld", test64); */
 	/* info("converted LD\t %Lf", test_double2); */