6lowpan: iphc: Fix parenthesis alignments which off-by-one

CHECK: Alignment should match open parenthesis
+	if (((hdr->flow_lbl[0] & 0x0F) == 0) &&
+	     (hdr->flow_lbl[1] == 0) && (hdr->flow_lbl[2] == 0)) {

CHECK: Alignment should match open parenthesis
+		if ((hdr->priority == 0) &&
+		   ((hdr->flow_lbl[0] & 0xF0) == 0)) {

CHECK: Alignment should match open parenthesis
+		if ((hdr->priority == 0) &&
+		   ((hdr->flow_lbl[0] & 0xF0) == 0)) {

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>