Correct signed hexadecimal integer ranges conversion

BZ: 165527

PFW does not convert hexadecimal signed range values correctly

This patch correct signed range values interpretation

Change-Id: I5c060c637781821b70b769cabc31347b0e5e5be1
Signed-off-by: Sylvain Pichon <sylvainx.pichon@intel.com>
diff --git a/parameter/IntegerParameterType.cpp b/parameter/IntegerParameterType.cpp
index b07194b..dfe5a45 100755
--- a/parameter/IntegerParameterType.cpp
+++ b/parameter/IntegerParameterType.cpp
@@ -105,11 +105,14 @@
 
             _uiMin = 1UL << uiSizeInBits;
 
-            signExtend((int32_t&)_uiMin);
         }
+        signExtend((int32_t&)_uiMin);
+
         if (xmlElement.hasAttribute("Max")) {
 
             _uiMax = (uint32_t)xmlElement.getAttributeSignedInteger("Max");
+
+            signExtend((int32_t&)_uiMax);
         } else {
 
             _uiMax = (1UL << uiSizeInBits) - 1;