Fix typo.

Submitted by:	Dmitry Morozovsky <marck rinet ru>
MFC after:	3 days
MFV r271223:

In dnode_sync(), do dnode_increase_indirection() before processing
the dn_next_nblkptr.

Illumos issue:
    5117 space map reallocation can cause corruption

MFC after:	3 days
MFV r271225:

Iterate through all the children instead of returning error when we hit
the first error.  This makes the error message give more information
rather than just the first device that causes problem.

Illumos issue:
    5118 When verifying or creating a storage pool, error messages only
	 show one device

MFC after:	2 weeks