arm64: mte: Fix the stack frame size warning in mte_dump_tag_range()

With 64K page configurations, the tags array stored on the stack of the
mte_dump_tag_range() function is 2048 bytes, triggering a compiler
warning when CONFIG_FRAME_WARN is enabled. Switch to a kmalloc()
allocation via mte_allocate_tag_storage().

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Fixes: 6dd8b1a0

 ("arm64: mte: Dump the MTE tags in the core file")
Reported-by: kernel test robot <lkp@intel.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220401151356.1674232-1-catalin.marinas@arm.com
Signed-off-by: Will Deacon <will@kernel.org>