uml: remove unused variables in the context switcher

This patch removes a variable which was not used in two functions.  Yet
another code cleanup, nothing really significant.

Please note that I could not test this on x86_64. I don't have the
hardware for it.

[ jdike - Bits of tidying around the affected code.  Also, it's fine on
x86_64 ]

Signed-off-by: Karol Swietlicki <magotari@gmail.com>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/um/sys-x86_64/syscalls.c b/arch/um/sys-x86_64/syscalls.c
index 86f6b18..e437ee2 100644
--- a/arch/um/sys-x86_64/syscalls.c
+++ b/arch/um/sys-x86_64/syscalls.c
@@ -105,7 +105,7 @@
 	return ret;
 }
 
-void arch_switch_to(struct task_struct *from, struct task_struct *to)
+void arch_switch_to(struct task_struct *to)
 {
 	if ((to->thread.arch.fs == 0) || (to->mm == NULL))
 		return;