edid: fix warning

src/lib/edid.c:1177: error: ‘y’ may be used uninitialized in this function

Warning is bogus, but seems my gcc (4.4.7 as shipped by RHEL-6)
isn't clever enougth to figure this on its own.  So help a bit
by explicitly initializing the variable.

Change-Id: Ia9f966c9c0a6bd92a9f41f1a4a3c8e49f258be37
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-on: http://review.coreboot.org/3501
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
1 file changed