amd/addrlib: mark numPipes as MAYBE_UNUSED in Addr::V1::EgBasedLib::SanityCheckMacroT...

amd/addrlib: mark numPipes as MAYBE_UNUSED in Addr::V1::EgBasedLib::SanityCheckMacroTiled (v2)

Only used, when asserts are enabled.

Fixes an unused-variable warning with GCC 8:
 ../../../src/amd/addrlib/r800/egbaddrlib.cpp: In member function 'int Addr::V1::EgBasedLib::SanityCheckMacroTiled(ADDR_TILEINFO*) const':
 ../../../src/amd/addrlib/r800/egbaddrlib.cpp:982:13: warning: unused variable 'numPipes' [-Wunused-variable]
      UINT_32 numPipes    = HwlGetPipes(pTileInfo);
              ^~~~~~~~

v2: Don't realign other variable definitions, to keep in line with file
    style (Marek)

Signed-off-by: Kai Wasserbäch <kai@dev.carbon-project.org>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>