sys/dev/mps/mps.c
sys/dev/mps/mps_user.c
	Fix uninitialized memory reference in mps_read_config_page.  It was
	referencing a field (params->hdr.Ext.ExtPageType) that would only be
	set when reading an Extended config page.  The symptom was that
	MPSIO_READ_CFG_PAGE ioctls would randomly fail with
	MPI2_IOCSTATUS_CONFIG_INVALID_PAGE errors.  The solution is to
	determine whether an extended or an ordinary config page is requested
	by looking at the PageType field, which should be available regardless.

	Similarly, mps_user_read_extcfg_header and mps_user_read_extcfg_page,
	which call mps_read_config_page, had to be fixed to always set the
	PageType field.  They were implicitly assuming that
	mps_read_config_page always operated on Extended pages.

Reviewed by:	ken
Approved by:	ken (mentor)
MFC after:	3 days
In vm_object_split(), busy and consequently unbusy the pages only when
swap_pager_copy() is invoked, otherwise there is no reason to do so.
This will eliminate the necessity to busy pages most of the times.

Sponsored by:	EMC / Isilon storage division
Reviewed by:	alc