s390/sclp_early: Get rid of sclp_early_read_info_sccb_valid

s390/sclp_early: Get rid of sclp_early_read_info_sccb_valid

The early sclp detect functions gather the available SCLP facility information.
The sclp_early_read_info_sccb_valid indicates whether the early sclp request
was valid.  However, one external reference to it checks for particular sclp
facility bits and this should be sufficient.   Another occurance is in the
sclp_get_ipl_info() function that is called later.  Because all information are
available at the early stage, save the ipl information when detecting the sclp
facilities.  Hence, no more checks for sclp_early_read_info_sccb_valid are
required.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>