Remove test that is always true

src/libckpool.c

@@ -2047,13 +2047,11 @@ double diff_from_nbits(char *nbits)
 
 	pow = nbits[0];
 	powdiff = (8 * (0x1d - 3)) - (8 * (pow - 3));
-	if (powdiff < 8)
+	if (powdiff < 8) // testnet only
 		powdiff = 8;
 	diff32 = be32toh(*((uint32_t *)nbits)) & 0x00FFFFFF;
-	if (likely(powdiff > 0))
 	numerator = 0xFFFFULL << powdiff;
-	else
-		numerator = 0xFFFFULL >> -powdiff;
+
 	return numerator / (double)diff32;
 }