Increase the allowed length of device names to 63 characters.

This is a band-aid while I fret over how much breakage removing the
restriction entirely will result in.

Please note that this is still a limit for the entire pathname
relative to the mountpoint of devfs, so the length of "/dev/fd/3"
is 4 characters.

sys/sys/param.h

@@ -83,7 +83,7 @@
 #define	NOFILE		OPEN_MAX	/* max open files per process */
 #define	NOGROUP		65535		/* marker for empty group set member */
 #define MAXHOSTNAMELEN	256		/* max hostname size */
-#define SPECNAMELEN	15		/* max length of devicename */
+#define SPECNAMELEN	63		/* max length of devicename */
 
 /* More types and definitions used throughout the kernel. */
 #ifdef _KERNEL