qbman_portal.c: Update BUG_ON() call in qbman_swp_mc_submit

With gcc-5.x we get a warning about the ambiguity of BUG_ON(!a != b) and
becomes BUG_ON((!a) != b).  In this case reading of the function leads to
us wanting to rewrite this as BUG_ON(a != b).

Cc: Prabhakar Kushwaha <prabhakar@freescale.com>
Cc: Geoff Thorpe <Geoff.Thorpe@freescale.com>
Cc: Haiying Wang <Haiying.Wang@freescale.com>
Cc: Roy Pledge <Roy.Pledge@freescale.com>
Cc: York Sun <yorksun@freescale.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: York Sun <yorksun@freescale.com>
diff --git a/drivers/net/fsl-mc/dpio/qbman_portal.c b/drivers/net/fsl-mc/dpio/qbman_portal.c
index 5fa8d95..449ff8a 100644
--- a/drivers/net/fsl-mc/dpio/qbman_portal.c
+++ b/drivers/net/fsl-mc/dpio/qbman_portal.c
@@ -117,7 +117,7 @@
 {
 	uint32_t *v = cmd;
 #ifdef QBMAN_CHECKING
-	BUG_ON(!p->mc.check != swp_mc_can_submit);
+	BUG_ON(p->mc.check != swp_mc_can_submit);
 #endif
 	lwsync();
 	/* TBD: "|=" is going to hurt performance. Need to move as many fields