mm/memblock: fix a typo in comment "implict"->"implicit"

There is a typo in commet, fix it.
Signed-off-by: Ethon Paul <ethp@qq.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Link: http://lkml.kernel.org/r/20200411070701.16097-1-ethp@qq.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memblock.c

@@ -78,7 +78,7 @@
  * * memblock_alloc*() - these functions return the **virtual** address
  *   of the allocated memory.
  *
- * Note, that both API variants use implict assumptions about allowed
+ * Note, that both API variants use implicit assumptions about allowed
  * memory ranges and the fallback methods. Consult the documentation
  * of memblock_alloc_internal() and memblock_alloc_range_nid()
  * functions for more elaborate description.