powerpc: xmon: remove unused variables

Randconfig testing with W=1 showed up these warnings that I'd like to enable
by default:

arch/powerpc/xmon/xmon.c: In function 'dump_tlb_book3e':
arch/powerpc/xmon/xmon.c:3833:42: error: variable 'lrat' set but not used [-Werror=unused-but-set-variable]
 3833 |  int i, tlb, ntlbs, pidsz, lpidsz, rasz, lrat = 0;
      |                                          ^~~~
arch/powerpc/xmon/xmon.c:3831:23: error: variable 'lpidmask' set but not used [-Werror=unused-but-set-variable]
 3831 |  u32 mmucfg, pidmask, lpidmask;
      |                       ^~~~~~~~
arch/powerpc/xmon/xmon.c:3831:14: error: variable 'pidmask' set but not used [-Werror=unused-but-set-variable]
 3831 |  u32 mmucfg, pidmask, lpidmask;
      |              ^~~~~~~

Just remove these as they have been unused since the code was added in 2010.

Fixes: 03247157 ("powerpc/book3e: Add TLB dump in xmon for Book3E")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230809131024.2039647-2-arnd@kernel.org