revert apebrk.  changes applied in the wrong direction.

Reference: /n/atom/patch/applied2013/apebrkrevert
Date: Thu Aug  1 05:03:27 CES 2013
Signed-off-by: quanstro@quanstro.net

--- /sys/src/ape/lib/ap/plan9/sys9.h	Thu Aug  1 05:02:31 2013
+++ /sys/src/ape/lib/ap/plan9/sys9.h	Thu Aug  1 05:02:32 2013
@@ -77,6 +77,7 @@
 extern	int	_AWAIT(char*, int);
 extern	int	_ALARM(unsigned long);
 extern	int	_BIND(const char*, const char*, int);
+extern	int	_BRK_(void*);
 extern	int	_CHDIR(const char*);
 extern	int	_CLOSE(int);
 extern	int	_CREATE(char*, int, unsigned long);
--- /sys/src/ape/lib/9/libc.h	Thu Aug  1 05:02:33 2013
+++ /sys/src/ape/lib/9/libc.h	Thu Aug  1 05:02:34 2013
@@ -70,6 +70,7 @@
 extern	int	_AWAIT(char*, int);
 extern	int	_ALARM(unsigned long);
 extern	int	_BIND(const char*, const char*, int);
+extern	int	_BRK_(void*);
 extern	int	_CHDIR(const char*);
 extern	int	_CLOSE(int);
 extern	int	_CREATE(char*, int, unsigned long);
--- /sys/src/ape/lib/ap/plan9/brk.c	Thu Aug  1 05:02:35 2013
+++ /sys/src/ape/lib/ap/plan9/brk.c	Thu Aug  1 05:02:36 2013
@@ -5,7 +5,6 @@
 
 char	end[];
 static	char	*bloc = { end };
-extern	int	_BRK_(void*);
 
 enum
 {