extract_distfiles(): after extracting if $wrksrc doesn't exist, create

it.

--HG--
extra : convert_revision : b72bf0188c83e9a676448ba5da3ca1b25c4df493

xbps-src/shutils/extract_funcs.sh

@@ -172,5 +172,8 @@ extract_distfiles()
 		esac
 	done
 
+	if [ ! -d ${wrksrc} ]; then
+		mkdir -p ${wrksrc}
+	fi
 	touch -f $XBPS_EXTRACT_DONE
 }