drm/i915/bios: cleanup return type of intel_parse_bios()

These are unintuitive.  These are type bool and return -1 casted to true
on failure.  Let's just make it return an int.  The callers don't care,
but let's change this as a cleanup.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/i915/intel_bios.h b/drivers/gpu/drm/i915/intel_bios.h
index dbda6e3..31c2107 100644
--- a/drivers/gpu/drm/i915/intel_bios.h
+++ b/drivers/gpu/drm/i915/intel_bios.h
@@ -476,7 +476,7 @@
 } __attribute__ ((packed));
 
 void intel_setup_bios(struct drm_device *dev);
-bool intel_parse_bios(struct drm_device *dev);
+int intel_parse_bios(struct drm_device *dev);
 
 /*
  * Driver<->VBIOS interaction occurs through scratch bits in