Fix error message in OpenCL engine config function.

oclengine.c

@@ -2712,7 +2712,7 @@ vg_ocl_context_new_from_devstr(vg_context_t *vcp, const char *devstr,
 			nthreads = atoi(param);
 			if (nthreads == 0) {
 				fprintf(stderr,
-					"Invalid thread count '%s'\n", optarg);
+					"Invalid thread count '%s'\n", param);
 				continue;
 			}
 		}

pattern.h

@@ -35,7 +35,7 @@
 #include <unistd.h>
 #endif
 
-#define VANITYGEN_VERSION "0.21"
+#define VANITYGEN_VERSION "0.22pre"
 
 typedef struct _vg_context_s vg_context_t;