binconfig: Use d.getVar

The bb.data API is deprecated, use d.getVar instead.

index cbc4173..8591308 100644
@@ -21,8 +21,8 @@ def get_binconfig_mangle(d):

         s += " -e 's:OEEXECPREFIX:${STAGING_DIR_HOST}${exec_prefix}:'" s += " -e 's:-I${WORKDIR}:-I${STAGING_INCDIR}:'"
         s += " -e 's:-L${WORKDIR}:-L${STAGING_LIBDIR}:'"
-        if bb.data.getVar("OE_BINCONFIG_EXTRA_MANGLE", d):
-            s += bb.data.getVar("OE_BINCONFIG_EXTRA_MANGLE", d) +        if d.getVar("OE_BINCONFIG_EXTRA_MANGLE", False):
+            s += d.getVar("OE_BINCONFIG_EXTRA_MANGLE", True)
     return s