sys: Remove two double words in source code comments

- s/of of/of/

MFC after:	5 days

sys/sys/link_elf.h

@@ -58,7 +58,7 @@ typedef struct link_map {
 	caddr_t		l_base;			/* Base Address of library */
 	const char	*l_name;		/* Absolute Path to Library */
 	const void	*l_ld;			/* Pointer to .dynamic in memory */
-	struct link_map	*l_next, *l_prev;	/* linked list of of mapped libs */
+	struct link_map	*l_next, *l_prev;	/* linked list of mapped libs */
 	caddr_t		l_addr;			/* Load Offset of library */
 	const char	*l_refname;		/* object we are filtering for */
 } Link_map;

sys/sys/types.h

@@ -317,7 +317,7 @@ typedef	_Bool	bool;
  * The major and minor numbers are encoded in dev_t as MMMmmmMm (where
  * letters correspond to bytes).  The encoding of the lower 4 bytes is
  * constrained by compatibility with 16-bit and 32-bit dev_t's.  The
- * encoding of of the upper 4 bytes is the least unnatural one consistent
+ * encoding of the upper 4 bytes is the least unnatural one consistent
  * with this and other constraints.  Also, the decoding of the m bytes by
  * minor() is unnatural to maximize compatibility subject to not discarding
  * bits.  The upper m byte is shifted into the position of the lower M byte