x86/boot/e820: Remove e820__range_remove()'s unused return parameter

None of the usage sites make use of the 'real_removed_size'
return parameter of e820__range_remove(), and it's hard
to contemplate much constructive use: E820 maps can have
holes, and removing a fixed range may result in removal
of any number of bytes from 0 to the requested size.

So remove this pointless calculation. This simplifies
the function a bit:

   text       data        bss        dec        hex    filename
   7645      44072          0      51717       ca05    e820.o.before
   7597      44072          0      51669       c9d5    e820.o.after

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: H . Peter Anvin <hpa@zytor.com>
Cc: Andy Shevchenko <andy@kernel.org>
Cc: Arnd Bergmann <arnd@kernel.org>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Paul Menzel <pmenzel@molgen.mpg.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/20250515120549.2820541-27-mingo@kernel.org

Author: ingomolnar

arch/x86/include/asm/e820/api.h

@@ -16,7 +16,7 @@ extern bool e820__mapped_all(u64 start, u64 end, enum e820_type type);
 
 extern void e820__range_add   (u64 start, u64 size, enum e820_type type);
 extern u64  e820__range_update(u64 start, u64 size, enum e820_type old_type, enum e820_type new_type);
-extern u64  e820__range_remove(u64 start, u64 size, enum e820_type old_type, bool check_type);
+extern void e820__range_remove(u64 start, u64 size, enum e820_type old_type, bool check_type);
 extern u64  e820__range_update_table(struct e820_table *t, u64 start, u64 size, enum e820_type old_type, enum e820_type new_type);
 
 extern int  e820__update_table(struct e820_table *table);

arch/x86/kernel/e820.c

@@ -548,11 +548,10 @@ __init u64 e820__range_update_table(struct e820_table *t, u64 start, u64 size,
 }
 
 /* Remove a range of memory from the E820 table: */
-__init u64 e820__range_remove(u64 start, u64 size, enum e820_type old_type, bool check_type)
+__init void e820__range_remove(u64 start, u64 size, enum e820_type old_type, bool check_type)
 {
 	u32 idx;
 	u64 end;
-	u64 real_removed_size = 0;
 
 	if (size > (ULLONG_MAX - start))
 		size = ULLONG_MAX - start;
@@ -575,7 +574,6 @@ __init u64 e820__range_remove(u64 start, u64 size, enum e820_type old_type, bool
 
 		/* Completely covered? */
 		if (entry->addr >= start && entry_end <= end) {
-			real_removed_size += entry->size;
 			memset(entry, 0, sizeof(*entry));
 			continue;
 		}
@@ -584,7 +582,6 @@ __init u64 e820__range_remove(u64 start, u64 size, enum e820_type old_type, bool
 		if (entry->addr < start && entry_end > end) {
 			e820__range_add(end, entry_end - end, entry->type);
 			entry->size = start - entry->addr;
-			real_removed_size += size;
 			continue;
 		}
 
@@ -594,8 +591,6 @@ __init u64 e820__range_remove(u64 start, u64 size, enum e820_type old_type, bool
 		if (final_start >= final_end)
 			continue;
 
-		real_removed_size += final_end - final_start;
-
 		/*
 		 * Left range could be head or tail, so need to update
 		 * the size first:
@@ -606,7 +601,6 @@ __init u64 e820__range_remove(u64 start, u64 size, enum e820_type old_type, bool
 
 		entry->addr = final_end;
 	}
-	return real_removed_size;
 }
 
 __init void e820__update_table_print(void)