-sys/queue.h in proc.c, and nuke the unnecessary C++ header guards stuff and

sys/cdefs.h in vis.h (it causes problems on some platforms). Reported by
someone on GitHub, issue 212.

compat/vis.h

@@ -73,9 +73,6 @@
  */
 #define	UNVIS_END	1	/* no more characters */
 
-#include <sys/cdefs.h>
-
-__BEGIN_DECLS
 char	*vis(char *, int, int, int);
 int	strvis(char *, const char *, int);
 int	stravis(char **, const char *, int);
@@ -85,6 +82,4 @@ int	strunvis(char *, const char *);
 int	unvis(char *, char, int *, int);
 ssize_t strnunvis(char *, const char *, size_t);
 
-__END_DECLS
-
 #endif /* !_VIS_H_ */

proc.c

@@ -17,7 +17,6 @@
  */
 
 #include <sys/types.h>
-#include <sys/queue.h>
 #include <sys/uio.h>
 
 #include <errno.h>