OvmfPkg: SataControllerDxe: add cascading error handling to Start()

OvmfPkg: SataControllerDxe: add cascading error handling to Start()

In the next patch we'll add another PCI operation to
SataControllerStart(), which, on error, has to be rolled back similarly to
other actions already being done in SataControllerStart(). Since that PCI
operation won't provide a non-NULL pointer on success, its rollback isn't
really suitable for the current error handling in SataControllerStart().

Employ the traditional cascading labels instead.

Cc: Alexander Graf <agraf@suse.de>
Cc: Reza Jelveh <reza.jelveh@tuhh.de>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Gabriel L. Somlo <somlo@cmu.edu>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Gabriel Somlo <somlo@cmu.edu>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18527 6f19259b-4bc3-4df7-8a09-765794883524