powerpc/fadump: Account for memory_limit while reserving memory

powerpc/fadump: Account for memory_limit while reserving memory

If the memory chunk found for reserving memory overshoots the memory
limit imposed, do not proceed with reserving memory. Default behavior
was this until commit c2152bec8f06 ("powerpc/fadump: consider reserved
ranges while reserving memory") changed it unwittingly.

Fixes: c2152bec8f06 ("powerpc/fadump: consider reserved ranges while reserving memory")
Cc: stable@vger.kernel.org
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/159057266320.22331.6571453892066907320.stgit@hbathini.in.ibm.com