drm/i915: Simplify onion for bxt_ddi_phy_init()

Older compilers (gcc-4.9) are not as able to track uninitialised
variables as well as more recent compilers. In particular,

drivers/gpu/drm/i915/intel_dpio_phy.c: In function ‘bxt_ddi_phy_init’:
drivers/gpu/drm/i915/intel_dpio_phy.c:482:25: warning: ‘was_enabled’ may be used uninitialized in this function [-Wmaybe-uninitialized]

In this case, we can rearrange code slightly to make the control flow
clearer to the reader, as well as the compiler. That is we only call
uninit using the same predicate as calling init
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171107135324.28300-1-chris@chris-wilson.co.ukReviewed-by: NGabriel Krisman Bertazi <krisman@collabora.co.uk>

drivers/gpu/drm/i915/intel_dpio_phy.c

@@ -466,21 +466,21 @@ void bxt_ddi_phy_init(struct drm_i915_private *dev_priv, enum dpio_phy phy)
 
 	lockdep_assert_held(&dev_priv->power_domains.lock);
 
-	if (rcomp_phy != -1) {
+	was_enabled = true;
+	if (rcomp_phy != -1)
 		was_enabled = bxt_ddi_phy_is_enabled(dev_priv, rcomp_phy);
 
-		/*
-		 * We need to copy the GRC calibration value from rcomp_phy,
-		 * so make sure it's powered up.
-		 */
-		if (!was_enabled)
-			_bxt_ddi_phy_init(dev_priv, rcomp_phy);
-	}
+	/*
+	 * We need to copy the GRC calibration value from rcomp_phy,
+	 * so make sure it's powered up.
+	 */
+	if (!was_enabled)
+		_bxt_ddi_phy_init(dev_priv, rcomp_phy);
 
 	_bxt_ddi_phy_init(dev_priv, phy);
 
-	if (rcomp_phy != -1 && !was_enabled)
-		bxt_ddi_phy_uninit(dev_priv, phy_info->rcomp_phy);
+	if (!was_enabled)
+		bxt_ddi_phy_uninit(dev_priv, rcomp_phy);
 }
 
 static bool __printf(6, 7)