x86/tools: Fix gcc-7 warning in relocs.c

x86/tools: Fix gcc-7 warning in relocs.c

gcc-7 warns:

In file included from arch/x86/tools/relocs_64.c:17:0:
arch/x86/tools/relocs.c: In function ‘process_64’:
arch/x86/tools/relocs.c:953:2: warning: argument 1 null where non-null expected [-Wnonnull]
  qsort(r->offset, r->count, sizeof(r->offset[0]), cmp_relocs);
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from arch/x86/tools/relocs.h:6:0,
                 from arch/x86/tools/relocs_64.c:1:
/usr/include/stdlib.h:741:13: note: in a call to function ‘qsort’ declared here
 extern void qsort

This happens because relocs16 is not used for ELF_BITS == 64,
so there is no point in trying to sort it.

Make the sort_relocs(&relocs16) call 32bit only.

Signed-off-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Link: http://lkml.kernel.org/r/20161215124513.GA289@x4
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[dongkyun.s: cherry-pick mainline commit 7ebb91678294 for gcc 9 build]

Change-Id: I1d521280f297d09a8a93af70cf3039e86b2b86e5