mm/memblock.c: fix a typo in __next_mem_pfn_range() comments

Link: http://lkml.kernel.org/r/20181107100247.13359-1-rainccrun@gmail.comSigned-off-by: NChen Chang <rainccrun@gmail.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NMike Rapoport <rppt@linux.ibm.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mm/memblock.c

@@ -1179,7 +1179,7 @@ void __init_memblock __next_mem_range_rev(u64 *idx, int nid,
 
 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
 /*
- * Common iterator interface used to define for_each_mem_range().
+ * Common iterator interface used to define for_each_mem_pfn_range().
  */
 void __init_memblock __next_mem_pfn_range(int *idx, int nid,
 				unsigned long *out_start_pfn,