Documented the dump_setpath function.

doc/new_chapters/dumpcontrol.t

@@ -16,7 +16,7 @@ process dump control manager is ...
 The directives provided by the process dump control manager are:
 
 @itemize @bullet
-@item @code{dump_setpath} - 
+@item @code{dump_setpath} - Dump File Control 
 @end itemize
 
 @section Background
@@ -31,13 +31,14 @@ and describes the calling sequence, related constants, usage,
 and status codes.
 
 @page
-@subsection dump_setpath - 
+@subsection dump_setpath - Dump File Control
 
 @subheading CALLING SEQUENCE:
 
 @ifset is-C
 @example
 int dump_setpath(
+  const char      *path
 );
 @end example
 @end ifset
@@ -48,12 +49,29 @@ int dump_setpath(
 @subheading STATUS CODES:
 
 @table @b
-@item E
+@item EACESS
-The
+Search permission is denied for a component of the path prefix,
+or write permission is denied on the directory containing the 
+file.
+@item ENAMETOOLONG
+The length of the argument exceeds {PATH_MAX} or a pathname
+component is longer than {NAME_MAX} while {_POSIX_NO_TRUNC}
+is in effect.
+@item ENOENT
+The path argument points to an empty string.
+@item ENOSYS
+The function dump_setpath() is not suppo9rted by this implementation.
+@item ENOTDIR
+A component of the path prefix is not a directory.
+@item EROFS
+The directory entry specified resides on a read-only file system.
 
 @end table
 
 @subheading DESCRIPTION:
 
+The @code{dump_setpath} function defines the pathname where process
+dumps are written.
+
 @subheading NOTES: