mm/mm_init.c: append newline to the unavailable ranges log-message

mm/mm_init.c: append newline to the unavailable ranges log-message

Based on the init_unavailable_range() method and it's callee semantics no
multi-line info messages are intended to be printed to the console.  Thus
append the '\n' symbol to the respective info string.

Link: https://lkml.kernel.org/r/20231122182419.30633-7-fancer.lancer@gmail.com
Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>