fix misspelling of a legacy macro name in sys/param.h

include/sys/param.h

@@ -7,7 +7,7 @@
 #define MAXPATHLEN 4096
 #define NBBY 8
 #define NGROUPS 32
-#define CANBSIZE 255
+#define CANBSIZ 255
 #define NOFILE 256
 #define NCARGS 131072
 #define DEV_BSIZE 512