arch/um/kernel/ptrace.c: remove dead PROC_MM

PROC_MM doesn't exist in Kconfig.  Looking around it looks like a
left-over from 2.6.0 or even 2.4 times, last mentioned in a fedora patch
for 2.6.10.  I believe it's time to get rid of that last tiny parts here
that are still around.

Signed-off-by: Christoph Egger <siccegge@cs.fau.de>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/um/kernel/ptrace.c

@@ -7,9 +7,6 @@
 #include "linux/ptrace.h"
 #include "linux/sched.h"
 #include "asm/uaccess.h"
-#ifdef CONFIG_PROC_MM
-#include "proc_mm.h"
-#endif
 #include "skas_ptrace.h"
 
 
@@ -158,24 +155,6 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 		break;
 	}
 #endif
-#ifdef CONFIG_PROC_MM
-	case PTRACE_SWITCH_MM: {
-		struct mm_struct *old = child->mm;
-		struct mm_struct *new = proc_mm_get_mm(data);
-
-		if (IS_ERR(new)) {
-			ret = PTR_ERR(new);
-			break;
-		}
-
-		atomic_inc(&new->mm_users);
-		child->mm = new;
-		child->active_mm = new;
-		mmput(old);
-		ret = 0;
-		break;
-	}
-#endif
 #ifdef PTRACE_ARCH_PRCTL
 	case PTRACE_ARCH_PRCTL:
 		/* XXX Calls ptrace on the host - needs some SMP thinking */