libxerces-c: fix pkgconfig paths

Signed-off-by: Rosen Penev <rosenp@gmail.com>

libs/libxerces-c/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=xerces-c
 PKG_VERSION:=3.2.3
-PKG_RELEASE:=2
+PKG_RELEASE:=3
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
 PKG_SOURCE_URL:=@APACHE/xerces/c/3/sources
@@ -74,6 +74,8 @@ define Build/InstallDev
 	$(CP) $(PKG_INSTALL_DIR)/usr/lib/cmake/XercesC/* $(1)/usr/lib/cmake/XercesC
 	$(INSTALL_DIR) $(1)/usr/lib/pkgconfig
 	$(CP) $(PKG_INSTALL_DIR)/usr/lib/pkgconfig/xerces-c.pc $(1)/usr/lib/pkgconfig/xerces-c.pc
+	$(SED) 's,/usr/include,$$$${prefix}/include,g' $(1)/usr/lib/pkgconfig/xerces-c.pc
+	$(SED) 's,/usr/lib,$$$${exec_prefix}/lib,g' $(1)/usr/lib/pkgconfig/xerces-c.pc
 endef
 
 define Package/libxerces-c/install