x86/boot/e820: Basic cleanup of e820.c

Over the last decade or so e820.c has become an ureadable mess of
tinkerware. Perform some very basic cleanups before doing more
intricate cleanups, so that my eyes don't start bleeding when I look at it.

Here's some of the excesses:

 - Total disregard of countless aspects of Documentation/CodingStyle.

 - Totally inconsistent hodge-podge of various coding styles and practices.

 - Gems like:

       (unsigned long long) e820_table->entries[i].addr

   ... which is a completely unnecessary type conversion of an u64 value.

 - Incomprehensible comments while there are major functions with absolutely
   no explanation - plus an armada of typos and grammar mistakes.

 - Mindless checkpatch artifacts such as:

         if (append_e820_table(boot_params.e820_table, boot_params.e820_entries)
           < 0) {

           for_each_free_mem_range(u, NUMA_NO_NODE, MEMBLOCK_NONE, &start, &end,
                                   NULL) {

 - Actively misleading comments:

        /* In case someone cares... */
        return who;

   ( The usage site of the return value just a few lines further down makes it
     clear that we very much care about the return value, we use it to print
     out the e820 map... )

 - Colorfully inconsistent capitalization and punctuation throughout.

 - etc.

This patch fixes only the worst excesses - there's more to fix.

No change in functionality.

Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang, Ying <ying.huang@intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Jackson <pj@sgi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>