Changed xmlSearchNsByHref to call xmlNsInScope with the prefix instead of

* tree.c: Changed xmlSearchNsByHref to call xmlNsInScope with
  the prefix instead of the namespace name.
* test/schemas/annot-err_0.xsd test/schemas/element-err_0.xsd:
  Adapted invalid values of the "id" attribute, since they are
  validated now.
diff --git a/test/schemas/element-err_0.xsd b/test/schemas/element-err_0.xsd
index a5c696f..92604c8 100644
--- a/test/schemas/element-err_0.xsd
+++ b/test/schemas/element-err_0.xsd
@@ -17,7 +17,7 @@
 			<xsd:sequence>
 				<xsd:element ref="foo:bar" name="myomy" minOccurs="3" 
 					maxOccurs="2" abstract="true" block="flute"
-					form="qualified" id="b12" nillable="true" 
+					form="qualified" id="b13" nillable="true" 
 					substitutionGroup="foo:bar" type="xsd:string" 
 					default="Jimi" fixed="Hendrix" final="fantasy">
 					<xsd:complexType/>
@@ -25,7 +25,7 @@
 				</xsd:element>
 				<xsd:element name="myomy" maxOccurs="0"
 					abstract="true" block="flute"
-					form="qualified" id="b12" nillable="true" 
+					form="qualified" id="b14" nillable="true" 
 					substitutionGroup="foo:bar" type="xsd:string" 
 					default="Jimi" fixed="Hendrix" final="fantasy">
 					<xsd:complexType/>