mm: memblock: drop __init from memblock functions to make it inline

__init is used with inline due to which memblock wraper functions are
not getting inline.
for example:
[    0.000000] memblock_alloc_try_nid: 1490 bytes align=0x40 nid=-1 from=0x0000000000000000 max_addr=0x0000000000000000 memblock_alloc+0x20/0x2c
[    0.000000] memblock_reserve: [0x000000023f09a3c0-0x000000023f09a991] memblock_alloc_range_nid+0xc0/0x188

Dropping __init from memblock wrapper functions to make it inline and it
increase the debugability.
After:
[    0.000000] memblock_alloc_try_nid: 1490 bytes align=0x40 nid=-1 from=0x0000000000000000 max_addr=0x0000000000000000 start_kernel+0xa4/0x568
[    0.000000] memblock_reserve: [0x000000023f09a3c0-0x000000023f09a991] memblock_alloc_range_nid+0xc0/0x188

Signed-off-by: Faiyaz Mohammed <faiyazm@codeaurora.org>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>