Correct -a command line help.

cpu-miner.c

@@ -63,7 +63,7 @@ static struct option_help options_help[] = {
 	  "(-h) Display this help text" },
 
 	{ "algo",
-	  "(-a) Specify sha256 implementation:\n"
+	  "(-a XXX) Specify sha256 implementation:\n"
 	  "\tc\t\tLinux kernel sha256, implemented in C"
 #ifdef __SSE__
 	  "\n\t4way\t\ttcatm's 4-way SSE2 implementation"