NOMMU: Don't check vm_region::vm_start is page aligned in add_nommu_region()

Don't check vm_region::vm_start is page aligned in add_nommu_region() because
the region may reflect some non-page-aligned mapped file, such as could be
obtained from RomFS XIP.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NGreg Ungerer <gerg@uclinux.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mm/nommu.c

@@ -515,8 +515,6 @@ static void add_nommu_region(struct vm_region *region)
 
 	validate_nommu_regions();
 
-	BUG_ON(region->vm_start & ~PAGE_MASK);
-
 	parent = NULL;
 	p = &nommu_region_tree.rb_node;
 	while (*p) {