drm/i915: simplify gmbus xfer error checks

Shorter, easier to follow code with no functional changes. In all cases,
the return value ultimately comes from gmbus_wait_hw_status() anyway.
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1448980166-23055-1-git-send-email-jani.nikula@intel.com

drivers/gpu/drm/i915/intel_i2c.c

@@ -505,17 +505,13 @@ gmbus_xfer(struct i2c_adapter *adapter,
 			ret = gmbus_xfer_write(dev_priv, &msgs[i]);
 		}
 
-		if (ret == -ETIMEDOUT)
-			goto timeout;
-		if (ret == -ENXIO)
-			goto clear_err;
-
+		if (!ret)
 			ret = gmbus_wait_hw_status(dev_priv, GMBUS_HW_WAIT_PHASE,
 						   GMBUS_HW_WAIT_EN);
-		if (ret == -ENXIO)
-			goto clear_err;
-		if (ret)
+		if (ret == -ETIMEDOUT)
 			goto timeout;
+		else if (ret)
+			goto clear_err;
 	}
 
 	/* Generate a STOP condition on the bus. Note that gmbus can't generata