um: Remove unused functions

These functions are not used anymore. Removing them will also address
below -Wmissing-prototypes warnings:

arch/um/kernel/process.c:51:5: warning: no previous prototype for ‘pid_to_processor_id’ [-Wmissing-prototypes]
arch/um/kernel/process.c:253:5: warning: no previous prototype for ‘copy_to_user_proc’ [-Wmissing-prototypes]
arch/um/kernel/process.c:263:5: warning: no previous prototype for ‘clear_user_proc’ [-Wmissing-prototypes]
arch/um/kernel/tlb.c:579:6: warning: no previous prototype for ‘flush_tlb_mm_range’ [-Wmissing-prototypes]
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

arch/um/kernel/process.c

@@ -48,17 +48,6 @@ static inline int external_pid(void)
 	return userspace_pid[0];
 }
 
-int pid_to_processor_id(int pid)
-{
-	int i;
-
-	for (i = 0; i < ncpus; i++) {
-		if (cpu_tasks[i].pid == pid)
-			return i;
-	}
-	return -1;
-}
-
 void free_stack(unsigned long stack, int order)
 {
 	free_pages(stack, order);
@@ -250,21 +239,11 @@ char *uml_strdup(const char *string)
 }
 EXPORT_SYMBOL(uml_strdup);
 
-int copy_to_user_proc(void __user *to, void *from, int size)
-{
-	return copy_to_user(to, from, size);
-}
-
 int copy_from_user_proc(void *to, void __user *from, int size)
 {
 	return copy_from_user(to, from, size);
 }
 
-int clear_user_proc(void __user *buf, int size)
-{
-	return clear_user(buf, size);
-}
-
 static atomic_t using_sysemu = ATOMIC_INIT(0);
 int sysemu_supported;
 

arch/um/kernel/tlb.c

@@ -576,12 +576,6 @@ void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
 }
 EXPORT_SYMBOL(flush_tlb_range);
 
-void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
-			unsigned long end)
-{
-	fix_range(mm, start, end, 0);
-}
-
 void flush_tlb_mm(struct mm_struct *mm)
 {
 	struct vm_area_struct *vma;